JPS59111761A - Sterilizing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sterilization method capable of processing large quantities of objects to be processed, such as food containers.

Conventionally, irradiation with a germicidal lamp has been used as one of the simple methods for sterilizing fungi.

Conventional germicidal lamps typically consume a few tens of watts of power, with special types consuming around 200 watts. Tasoshi,
When the power is about 200 watts, the length of the germicidal lamp becomes about 2 meters long, and the amount of germicidal radiation per unit arc length does not particularly increase significantly.

By the way, there are many types of fungi, and for example, in the case of fungi that absorb light well, such as black mold, only the black mold on the surface is sterilized, and the superimposed black mold located below the surface black mold is extremely sterilized. difficult to sterilize. Therefore, with conventional germicidal lamps, the sterilization time is long and the sterilization rate is low for bacteria that absorb light well, such as black mold.
There are drawbacks that make it not a very good sterilization method.

In general, the UV sterilization effect of germicidal lamps is determined by the following formula: % No: Number of bacteria after UV irradiation N: Number of bacteria after UV irradiation Q: Constant specific to bacteria t: UV rays in the wavelength range effective for sterilization Intensity 4: Intensity t of the ultraviolet rays irradiated to the surface layer of the bacteria. Irradiation time α: The above ultraviolet absorption coefficient of the bacteria - 2. Constant L: Depth from the surface of the bacterial layer. Therefore, from these equations, it can be seen that in order to effectively perform sterilization, it is sufficient to increase the value of 2-1. Since α and β are constants specific to Akane, the final decision is whether to increase t or ti. With conventional germicidal lamps, since t0 is small, t has to be increased, but even so, in the case of black mold, etc., only the surface layer could be sterilized, and the sterilization rate was low.

Furthermore, when sterilizing objects to be processed such as food containers and wrapping paper, a high sterilization rate is required, and in the unlikely event that a lamp or the like breaks during sterilization, its fragments may fall onto the objects to be processed. It is not allowed to adhere to the

Therefore, the purpose of the present invention is to provide a sterilization method that can safely and in large quantities process objects such as food containers and wrapping paper with a high sterilization rate. The purpose is to sterilize fungi on the surfaces of the objects by emitting light from a flash discharge lamp and irradiating the objects through the quartz wall as they move sequentially and reach a sterilization station.

Although flash discharge lamps themselves are already widely used in industry,
This flash discharge lamp contains a rare gas as a luminescent component, and its instantaneous luminescence is 104 to 101 times as strong as that of a germicidal lamp. Therefore, when used in the present invention, favorable results can be expected. According to experiments, at a irradiation distance of 10m, 1c
A sample containing ciJIQ' cultured black mold was placed, and as a conventional germicidal lamp, an arc length of 50 ounces and a voltage of 3
07. A lamp with a current of 0.8 A and a bulb inner diameter of 1.2 cm was designed for continuous irradiation, while a flash discharge lamp of the same size was used with an arc length of 30 crn, a bulb inner diameter of 1.2 cm, and a pulse width of 1 m (6). 0. (Duration at the height of 7 of Hals peak value: U wavefront length), one emission energy 200
When flash light is irradiated under the conditions of 5 joules per second, the number of bacteria after 10 seconds in the former is 104, and the number of bacteria in the latter is 10 after 8 seconds, in terms of sterilization rate. , the former is 9
9ch, and the latter was 99.999ch.

In terms of the number of remaining bacteria, the number of bacteria remaining when using a flash discharge lamp is about the same as when using a germicidal lamp.

000 In other words, it can be seen that when using a flash discharge lamp, a higher sterilization rate can be obtained in a shorter time than when using a germicidal lamp.

Next, the results of a sterilization experiment in a higher emission energy range will be explained. The samples and flash discharge lamps used were the same as above, but the number of flash discharge lamps was increased and the irradiation distance was increased by 2.
．． 5cIn, one emission energy is 600,90
It was changed to 0.1!150 joules. A quartz wall was interposed between the sample and the flash discharge lamp. The relationship between the sterilization rate of 106 black molds and the number of luminescence is shown in Fig. 1, where the broken line A is the characteristic curve at 1650 Joules, the broken line B is the characteristic curve at 900 Joules, and the broken line C is the characteristic curve at 600 Joules. For 1,350 Joules, it is only necessary to emit light once, for 900 Joules, it is necessary to emit light three times, and for 600 Joules, it is necessary to emit light seven times.It can be said that instantaneous irradiation with high energy is more effective at sterilizing, but in any case, it can be done in a short time. A high killing rate can be obtained. The same experiment was conducted without the quartz wall, but the results were almost the same, confirming that the quartz wall absorbs almost no ultraviolet light.

Next, FIG. 2 is an explanatory diagram of a method for sterilizing objects to be processed in a deep container, in which objects 1 to be processed are sequentially transported to a sterilization station by a belt conveyor 2 that moves continuously or intermittently. The irradiation lamp 3d can move up and down in the sterilization station when the conveyor 2 moves intermittently, and can move forward in synchronization with the conveyor 2 in addition to up and down movement when it moves continuously. The irradiation lamp 6 has a quartz wall 4 that can be inserted into the container.
is attached, and a flash discharge lamp 5 consisting of a U-shaped bulb xenon flash lamp emits light inside it. When a detector (not shown) detects that the object 1 to be treated has been transported to the sterilization station by the conveyor 2, the irradiation lamp 6
falls down and emits light inside the container, sterilizing it. However,
The workpiece 1 may be raised to receive the flash discharge lamp 5 inside the container. When the object 1 to be treated is a flat wrapping paper or a shallow container, an irradiation lamp 6 is constituted by a straight tube-shaped flash discharge lamp 5 and a flat quartz wall 4.
It is sterilized by placing it in close proximity and emitting light.

As described above, the present invention uses a flash discharge lamp with a significantly large instantaneous light output in place of a conventional germicidal lamp, resulting in a very high sterilization rate.Furthermore, since the object to be treated is irradiated through a quartz wall, it is possible to Even if one lamp is damaged, it is possible to prevent its fragments from adhering to the object to be processed, making it suitable for sterilizing objects such as food containers that cannot be allowed to contain foreign matter. Since the quartz wall does not absorb ultraviolet rays like bi-17x glass or ordinary glass, the presence of the quartz wall does not cause a problem of loss of output. In addition, since the objects to be processed are sequentially conveyed to the sterilization station by a conveyor or the like and are continuously processed at the station, there is also the advantage that the objects to be processed can be sterilized efficiently.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the data, and FIG. 2 is an explanatory diagram of the sterilization method. 1... Object to be treated 6... Irradiation lamp 4... Quartz wall 5... Flash discharge lamp Applicant USHIO INC. Co., Ltd. agent Patent attorney Toranosuke Tahara Figure 1 L @ Written amendment to this procedure (spontaneous) ) December 26, 1983 Kazuo Wakasugi, Commissioner of the Japan Patent Office1, Indication of the case 1988 Patent Application No. 2112592, Title of the invention Sterilization method 3, Relationship with the person making the amendment case Taizo Yumoto, representative of the patent applicant 4. Agent 6: Number of inventions increased by amendment N/A (1) The scope of claims is amended as follows. It is characterized by emitting light from a flash discharge lamp containing a rare gas as a major emitting component, and irradiating the light emitted through a quartz wall onto the workpieces that have moved sequentially and reached a sterilization station to sterilize fungi on the surface of the workpieces. sterilization method. (2) Correct "1 generated component" on page 4, line 6 of the specification box to "1 luminescent acid component."that's all

Claims (1)

[Claims] It is characterized by emitting light from a flash discharge lamp containing a rare gas as a generating component, and irradiating the light emitted through a quartz wall onto the workpieces that have moved sequentially and reached the sterilization station to sterilize fungi on the surface of the workpieces. Sterilization method.