JP2006026252A - Sterilizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sterilizer capable of reducing the temperature rising of an electrodeless discharge bulb when the irradiation of microwaves is continued exceedingly after the time required for the sterilization of an object to be treated. <P>SOLUTION: In the sterilizer provided with the electrodeless discharge bulb 2 housing a material for emitting ultraviolet rays by being irradiated with the microwaves in the inside for executing the sterilization treatment of a surface to be treated by irradiating the surface to be treated of the object 10 to be treated with the ultraviolet rays emitted from the electrodeless discharge bulb 2, the electrodeless discharge bulb 2 is constituted such that the relational expression of S/V>8[1/cm] is established at the time of defining the inner surface area as S and an inner volume as V, and the internal maximum straight distance of the electrodeless discharge bulb 2 is smaller than 1/2 of the wavelength of the microwaves. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sterilization apparatus for sterilizing an object to be processed with ultraviolet rays using a microwave generator such as a microwave oven in a general household.

As this type of sterilization apparatus, there is one disclosed in Japanese Patent Application Laid-Open No. 2004-147873. FIG. 10 is a perspective view in which a part of the sterilization apparatus disclosed therein is cut away.
This includes an electrodeless discharge bulb 2 that contains therein a substance that emits ultraviolet rays when irradiated with microwaves, a bulb support 3 that supports the electrodeless discharge bulb 2, and an object to be treated 10 to be treated. A holding unit 4 that holds the object to be processed 10 so that the surface faces the ultraviolet emission surface of the electrodeless discharge bulb 2 and a container 9 made of a material that transmits microwaves but does not transmit ultraviolet rays. Yes. The container 9 is divided into two substantially vessel-like bodies 9a and 9b that are openably and closably connected to each other, and each of the inner bottom portions of the substantially vessel-like bodies 9a and 9b has a valve support 3. Is arranged.
Here, the electrodeless discharge bulb 3 is formed by enclosing a rare gas and mercury in a small-diameter glass tube that transmits at least ultraviolet rays, and emits ultraviolet rays having a wavelength suitable for sterilization to the surroundings by microwaves in a microwave oven. is there.

Therefore, in this case, the object 10 is set in one of the substantially container-like bodies 9a, and in this state, the other substantially container-like body 9b is fitted and connected, and the container is composed of both substantially vessel-like bodies 9a and 9b. When 11 is closed and accommodated in a microwave oven, the electrodeless discharge bulb 2 emits ultraviolet rays having a wavelength suitable for sterilization to the surroundings by microwaves irradiated in the microwave oven, and the microwave oven is used. Thus, the surface to be processed of the object to be processed 10, that is, the front side surface and the back side surface of the object 10 can be sterilized.
JP 2004-147873 A

However, when the electrodeless discharge bulb 2 is irradiated with microwaves, a discharge occurs in the electrodeless discharge bulb 2, thereby generating plasma. Then, the electrons in the plasma are accelerated by the microwave and collide with neutral atoms and the inner wall, whereby the temperature of the electrodeless discharge bulb 2 rises. In particular, if the microwave irradiation continues after the time required for sterilization of the workpiece 10, the temperature of the electrodeless discharge bulb 2 may rise unexpectedly. Specifically, when the place to be sterilized is operated for about 10 minutes by operating the microwave oven for 3 minutes on the object to be processed 10, the temperature of the electrodeless discharge bulb 2 is supported by the bulb support 3. In some cases, the temperature rises above the heat resistant temperature.
Therefore, in order to prevent a problem even if the microwave oven is operated for a long time, special measures such as forming the valve support 3 with a ceramic material are required.

  The present invention has been made in view of the above-mentioned reasons, and its problem is to reduce the temperature rise of the electrodeless discharge bulb when the microwave irradiation is continued beyond the time necessary for sterilization of the workpiece. It is to provide a sterilizer that can.

  The sterilization apparatus of the present invention has an electrodeless discharge bulb containing therein a substance that emits ultraviolet rays when irradiated with microwaves, and the ultraviolet rays emitted from the electrodeless discharge bulb are treated with an object to be treated. In the sterilizing apparatus for sterilizing the surface to be processed by irradiating the surface, the electrodeless discharge bulb has S / V> 8 [1 / cm] when the inner surface area is S and the inner volume is V. The relational expression is established, and the maximum internal linear distance of the electrodeless discharge bulb is smaller than one half of the wavelength of the microwave.

  In the invention of claim 1, when the electrodeless discharge bulb has an inner surface area S and an inner volume V, a relational expression S / V> 8 [1 / cm] is established, and By making the internal maximum linear distance of the electrodeless discharge bulb smaller than one half of the wavelength of the microwave, the electrons used for maintaining the discharge disappear due to surface recombination, so that the microwave irradiation is applied to the workpiece. When the sterilization is continued beyond the time required for sterilization, the temperature rise of the electrodeless discharge bulb can be reduced.

(First embodiment)
A first embodiment corresponding to claims 1 and 2 of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view with a part of the sterilizer cut away, FIG. 2 is a conceptual diagram showing a state in which the sterilizer is accommodated in a microwave generator, FIG. 3 is a sectional view of an electrodeless discharge bulb, and FIG. It is a figure which shows the relationship between the time which irradiated and temperature of an electrodeless discharge bulb.

This sterilization apparatus includes an electrodeless discharge bulb 2 that contains a substance that emits ultraviolet rays when irradiated with microwaves, a valve support 3 that supports the electrodeless discharge bulb 2, and an object to be treated 10. A holding unit 4 that holds the workpiece 10 such that the processing surface faces the ultraviolet emission surface of the electrodeless discharge bulb 2, a container 9 made of a material that transmits microwaves but does not transmit ultraviolet rays, It is configured with.
In addition, the to-be-processed object 10 consists of the nipple tool 10a of the feeding bottle and the fixture 10b which attaches this here.

  The electrodeless discharge bulb 2 has a substantially cylindrical hollow quartz glass tube 2a sealed at both ends in the longitudinal direction, and an ultraviolet emitting substance 2b such as mercury vapor sealed inside the tube. The electrodeless discharge bulb 2 is supported by the bulb support 3 so as to irradiate ultraviolet rays emitted from mercury atoms and the like excited by receiving the electric field energy of the microwave toward the inside of the container 9. Here, a bulb support portion 3 is disposed and fixed on each of the inner bottom portions of both substantially container-like bodies 9 a and 9 b that become the container 9, and two electrodeless discharge bulbs 2 supported by the bulb support portions 3. Are opposed to each other in the vertical direction inside the container 9.

  More specifically, the quartz glass tube 2a of the electrodeless discharge bulb 2 has a thickness of 1 mm. The relational expression S / V> 8 [1 / cm] is established, where S is the inner surface area of the quartz glass tube 2a and V is the inner volume, and the maximum internal linear distance is the wavelength of the microwave. The electrodeless discharge bulb 2 (quartz glass tube 2a) has an inner diameter L of 0.4 cm so that it is smaller than half (half of the wavelength of the microwave is 6 cm as will be described later). And a substantially cylindrical inner space having a height H of 2 cm. (See FIG. 3) In addition, argon is sealed inside the quartz glass tube 2a as buttsfa gas.

  The bulb support portion 3 is made of a fluorine-based thermosetting resin having a heat resistant temperature of 200 ° C. or higher, and is molded simultaneously with the electrodeless discharge bulb 2 while being supported on the bulb support portion 3. The discharge bulb 2 is supported and fixed.

  The holding portion 4 has a plurality of holding pieces 4a arranged around the valve support portion 3, and each holding piece 4a has an opening 4b for engaging and holding the lower end opening edge portion of the baby bottle fitting 10b. Each opening 4b is opened upward, and the lower end opening edge portion of the fixture 10b is inserted into the opening 4b from above to be engaged and held. In addition, the to-be-processed object 10 is not restricted to a baby bottle and its components, What is necessary is just to sterilize and to be accommodated in the container 9 and held by the holding part 4.

  The container 9 has an oval shape, and both substantially container-like bodies 9a and 9b constituting the container 9 are formed of a material that transmits microwaves but does not transmit ultraviolet rays, for example, fluorine resin. In this case, it is preferable that the substantially container-like body 9b, which is located at least on the upper side and serves as a cover, transmits visible light. Further, it is possible to apply a fluorescent material to at least a part of the inner surface or the outer surface of both of the container bodies 9a and 9b, or to mix a fluorescent substance into the material of the both container bodies 9a and 9b. preferable. A plurality of leg pieces 9a1 protrude from the outer periphery of the bottom of the substantially container-like body 9a which is located on the lower side, and the container 9 is placed and held by each leg piece 9a1.

  Next, the usage method of this sterilizer will be described. A nipple device 10a of a baby bottle that has been previously washed with a detergent or the like is mounted on the mounting device 1b, and the inner peripheral thread surface of the mounting device 10b is inserted into the opening 4b of the holding unit 4 so The tool 10a and the fixture 10b) are placed on the holding portion 4 of the lower substantially container 9a. Then, the upper substantially container-like body 9b is fitted and joined to the lower substantially container-like body 9a, and the container 9 composed of the both substantially container-like bodies 9a and 9b is closed. As a result, the lower electrodeless discharge bulb 2 faces the inner surface of the workpiece 10 and the upper electrodeless discharge bulb 2 faces the outer surface of the workpiece 10.

As described above, with the object to be processed 10 accommodated and held in the container 9, the container 9 is accommodated and placed on the inner bottom surface 15a of the microwave oven 15 as a microwave generator as shown in FIG. Then, the door 15b is closed, the microwave oven 15 is started, and the microwave is irradiated toward the container 9.
The microwaves pass through the container 9 (both substantially container-like bodies 9a and 9b), and further pass through the workpiece 10 (nipple tool 10a and fixture 10b) to reach the lower electrodeless discharge bulb 2. At the same time, it passes only through the container 9 (both approximately container-like bodies 9a and 9b) and reaches the upper electrodeless discharge bulb 2 as well.

  The microwaves that have reached both electrodeless discharge bulbs 2 excite mercury atoms inside the electrodeless discharge bulb 2, and ultraviolet rays are emitted from the excited mercury atoms. Ultraviolet rays are emitted to the outside through the quartz glass tube 2a of the electrodeless discharge bulb 2, and are irradiated on each of the inner and outer surfaces of the workpiece 10. In this case, the ultraviolet rays emitted from the exposed ultraviolet emission surface of the lower electrodeless discharge bulb 2 are applied to the inner surface of the workpiece 1 and emitted from the exposed ultraviolet emission surface of the upper electrodeless discharge bulb 2. Ultraviolet rays are applied to the outer surface of the workpiece 1.

  The ultraviolet rays are ultraviolet rays having a sterilizing effect of, for example, 254 nm, and sterilize the inner surface and the outer surface of the workpiece 1. The sterilization apparatus according to this embodiment can be easily sterilized with ultraviolet rays by using a microwave oven 15 in a general household, that is, a device that generates a 2.45 GHz (wavelength 12 cm) micro.

  Here, the process in which ultraviolet rays are emitted from the electrodeless discharge bulb 2 will be described in detail. When the electrodeless discharge bulb 2 is irradiated with microwaves, the electrons inside the electrodeless discharge bulb 2 are accelerated and collide with mercury atoms to ionize them. And if the number of electrons increases to some extent, it becomes possible to sustain discharge by receiving direct energy from microwaves. In the state where the discharge is maintained, the electrons are accelerated by the electric field generated by the microwave and collide with the mercury atoms to ionize or excite the mercury atoms. When the excited mercury atom returns to the ground state, the energy difference is emitted as light. One excitation radiation wavelength of mercury is 254 nm ultraviolet light, and this light has a strong bactericidal action. Since electrons collide with neutral atoms and the inner wall of the hollow quartz glass tube 2a in addition to collision with mercury atoms, the temperature of the hollow quartz glass tube 2a rises.

  In addition, since argon is sealed as Batzfa gas, the electrodeless discharge bulb 2 can easily maintain discharge. That is, the electrons collide with the argon atoms and excite the argon atoms to a relatively stable metastable order. Since the energy level of the excited argon atom is very close to the ionization energy level of mercury, the mercury atom in the ground state collides with the argon atom in the metastable excited state to receive energy and ionize. This is called the Penning effect. As described above, the combination of argon and mercury makes it easy to ionize, in other words, discharge easily.

  Further, (inner surface area S) / (inner volume V) of the electrodeless discharge bulb 2 (quartz glass tube 2a) is calculated to be 10.99 [1 / cm]. The electrons generated in the electrodeless discharge bulb 2 are used for maintaining the discharge as described above, but the electrons disappear on the inner surface due to surface recombination. The rate of disappearance and generation can be expressed by the ratio between the inner surface area S and the inner volume V. When the ratio of the inner surface area S increases, the proportion of electrons lost on the inner surface increases, and the electrons used for maintaining the discharge. The ratio of becomes smaller. Therefore, transient temperature rise can be prevented. When the temperature rise of the electrodeless discharge bulb 2 was measured using a general household microwave oven 15 (set at 700 W for 10 minutes), the temperature stayed at about 150 ° C. as shown in FIG. It was. (In this case, sterilization of the workpiece 10 is completed in about 3 minutes.)

  On the other hand, in the case of a substantially cylindrical inner space having an inner diameter L of 0.6 cm and a height H of 2 cm, (inner surface area S) / (inner volume V) is calculated to be 7.66 [1 / cm]. At this time, the temperature of the electrodeless discharge bulb 2 rose to a temperature of about 230 ° C. Further, in the case of a substantially cylindrical inner space having an inner diameter L of 0.2 cm and a height H of 2 cm, (inner surface area S) / (inner volume V) is calculated to be 21.02 [1 / cm]. At that time, the temperature of the electrodeless discharge bulb 2 remained at about 110 ° C. However, if the temperature is reduced by reducing the internal volume, the amount of ultraviolet rays also decreases. In this case, measures such as increasing the number of electrodeless discharge bulbs 2 are necessary.

  According to this embodiment, the electrodeless discharge bulb 2 has a relational expression of S / V> 8 [1 / cm] when the inner surface area is S and the inner volume is V, and the electrodeless discharge When the maximum linear distance inside the bulb 2 is smaller than one half of the wavelength of the microwave, when the microwave irradiation is continued beyond the time necessary for sterilization of the workpiece 10, The temperature rise of the electrodeless discharge bulb 2 can be reduced. As a result, a fluorine-based thermosetting resin can be used for the bulb support portion 3 that supports the electrodeless discharge bulb 2, and the container 9 that supports the bulb support portion 3 can be made of polypropylene having a lower heat-resistant temperature. Resin can be used.

FIG. 9 collectively shows the calculation result of (inner surface area S) / (inner volume V) and the increase in temperature of the electrodeless discharge bulb 2 when the inner diameter L and the height H are changed.
Also, as the Butzfagus sealed in the quartz glass tube 2a, xenon, krypton, neon, or the like can be used.

(Second Embodiment)
A second embodiment corresponding to claims 1, 2, and 3 of the present invention will be described with reference to FIGS. FIG. 5 is a cross-sectional view of the electrodeless discharge bulb, FIG. 6 is an explanatory diagram showing the relationship between the inner surface area and the inner volume of the electrodeless discharge bulb and the temperature rise value at that time, and FIG. It is a figure which shows the relationship of the temperature of an electrode discharge bulb. This is a modification of the electrodeless discharge bulb 2 of the sterilization apparatus in the first embodiment, and the other components are the same as those described in the first embodiment.

  In this structure, in order to change the inner surface area and the inner volume of the electrodeless discharge bulb 2, a structure 2c is provided in the electrodeless discharge bulb 2. The structure 2c is a rod-shaped member having a substantially cylindrical shape, and is provided from one end side to the other end side of the electrodeless discharge bulb 2 along the axis of the electrodeless discharge bulb 2 having a substantially cylindrical shape. . The same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  Thus, by providing the structure 2c in the electrodeless discharge bulb 2 and changing the diameter of the central rod, which is the structure 2c, to 0.1 cm, 0.2 cm, and 0.3 cm, the inner surface area S, contents The product V changes as shown in FIG. (In FIG. 6, the electrodeless discharge bulb 2 (quartz glass tube 2a) shows the case where the inner diameter L is 0.6 cm and 0.8 cm, and the height H is 2 cm.)

  When the sterilizer configured in this way is placed in the microwave oven 15 and irradiated with microwaves, the temperature of the electrodeless discharge bulb 2 rises in the same manner as described in the first embodiment. The temperature at this time was as shown in FIG. From this result, it can be seen that the temperature can be lowered when S / V> 8 [1 / cm] when the internal surface area is S and the internal volume is V. FIG. 7 shows the result of temperature rise when the inner diameter L of the electrodeless discharge bulb 2 (quartz glass tube 2a) is 0.6 cm, the height H is 2 cm, and the structure 2c is 0.3 cm.

  This is an S / V when the inner surface area is S and the inner volume is V without changing the outer shape of the electrode discharge bulb 2 by arranging the substantially cylindrical structure 2c inside the electrodeless discharge bulb 2. The value of can be increased. Furthermore, since the outer surface area of the electrodeless discharge bulb 2 can be made larger than that described in the first embodiment, the area from which the ultraviolet rays are emitted can be increased, and the amount of ultraviolet radiation can be relatively increased.

  Although the structure 2c is provided on the central axis of the electrodeless discharge bulb 2, the inner surface area S and the inner volume V do not change even if the structure 2c slightly deviates from the central axis. Results will be obtained.

(Third embodiment)
A third embodiment corresponding to claims 1, 2, and 4 of the present invention will be described with reference to FIGS. 7 is a diagram showing the relationship between the time of microwave irradiation and the temperature of the electrodeless discharge bulb, FIG. 8 is a sectional view of the electrodeless discharge bulb, and FIG. 9 is the relationship between the inner surface area and the inner volume of the electrodeless discharge bulb. It is explanatory drawing which shows the temperature rise value at that time. This is a modification of the electrodeless discharge bulb 2 of the sterilization apparatus in the first embodiment, and the other components are the same as those described in the first embodiment.

  In this device, the inner surface area S and the inner volume V of the electrodeless discharge bulb 2 are changed by recessing a part of the quartz glass tube 2a inward. Specifically, as shown in FIG. 8, the electrodeless discharge bulb 2 has a substantially cylindrical shape in which both end portions are sealed and the central portion is constricted, and each dimension has an inner diameter L of 0.6 cm and a height H of 1. The hole diameter of the constricted portion is 0.3 cm. The same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  When the sterilizer configured in this way is placed in the microwave oven 15 and irradiated with microwaves, the temperature of the electrodeless discharge bulb 2 rises in the same manner as described in the first embodiment. As shown in FIG. 7, the temperature of the electrodeless discharge bulb 2 was 200 ° C. or lower.

  In this case, a part of the quartz glass tube 2a is recessed inward to increase the S / V value when the inner surface area is S and the inner volume is V without changing the outer diameter of the electrode discharge bulb 2. Can do. Furthermore, since the outer surface area of the electrodeless discharge bulb 2 can be made larger than that described in the first embodiment, the area from which the ultraviolet rays are emitted can be increased, and the amount of ultraviolet radiation can be relatively increased.

It is a figure which concerns on the 1st Embodiment of this invention, and is the perspective view which notched some sterilizers. It is a conceptual diagram which shows the state which accommodated the same sterilizer in the microwave generator. It is sectional drawing of an electrodeless discharge bulb same as the above. It is a figure which shows the relationship between the irradiation time when a sterilizer same as the above is accommodated in a microwave generator, and is irradiated with a microwave, and the temperature of an electrodeless discharge bulb. It is a figure which concerns on the 2nd Embodiment of this invention, and is sectional drawing of an electrodeless discharge bulb. It is explanatory drawing which shows the relationship between the internal surface area and internal volume of an electrodeless discharge bulb same as the above, and the temperature rise value at that time. The irradiation time and the temperature of the electrodeless discharge bulb when the sterilizer described in the second embodiment and the third embodiment of the present invention is accommodated in a microwave generator and irradiated with microwaves. It is a figure which shows the relationship. It is a figure which concerns on the 3rd Embodiment of this invention, and is sectional drawing of an electrodeless discharge bulb. It is explanatory drawing which shows the relationship between the internal surface area and internal volume of an electrodeless discharge bulb same as the above, and the temperature rise value at that time. It is the perspective view which notched a part of sterilizer based on a prior art example.

Explanation of symbols

2 Electrodeless discharge bulb 2a Quartz glass tube 2b Ultraviolet emitting substance 3 Valve support 4 Holding unit 9 Container 10 Processed object 15 Microwave oven S Internal surface area V Internal volume

Claims (4)

It has an electrodeless discharge bulb that contains a substance that emits ultraviolet rays when irradiated with microwaves, and the surface to be treated is irradiated with ultraviolet rays emitted from the electrodeless discharge bulb. In the sterilization apparatus for performing sterilization treatment of the treatment surface, the relational expression of S / V> 8 [1 / cm] is established when the electrodeless discharge bulb has an inner surface area S and an inner volume V, and The sterilizer characterized in that the maximum linear distance inside the electrodeless discharge bulb is smaller than one half of the wavelength of the microwave. The sterilizer according to claim 1, wherein the electrodeless discharge bulb has a substantially cylindrical shape. The sterilizer according to claim 1 or 2, wherein a substantially cylindrical structure is disposed inside the electrodeless discharge bulb. The sterilizer according to claim 1 or 2, wherein the electrodeless discharge bulb is formed of a glass tube and a part of the glass tube is recessed inward.

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