JPS6017539B2 - Continuous sterilization method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention is a method of sterilizing an object to be sterilized consisting of a flexible packaging body (retort pouch) in which a flexible packaging container is filled with food or the like.
It relates to a method of continuous sterilization using a sterilization temperature of ℃ or higher and a pressure of atmospheric pressure or higher.

In general, flexible packaging containers are easily damaged, unlike plastic packaging containers, so when continuously sterilizing flexible packaging as objects to be sterilized, the objects to be sterilized must be shaped like dishes. Damage to the peelable packaging container is prevented by storing it in a container and heating and sterilizing it while transporting the dish-shaped containers stacked in multiple tiers, followed by cooling.

In this continuous sterilization method, dish-shaped containers made of flexible packaging containing objects to be sterilized are stacked in multiple tiers, one above the other, and are fed from outside the device body to a conveyor installed inside the device body. The dish-shaped container is transported while being held horizontally by this transport conveyor, and is guided from the cooling water filled with the cooling water through the gas phase at the upper part of the device main body into the hot water filling the sterilization chamber. After the object to be sterilized is heated and sterilized with water, it is introduced into the cooling water filled in the cooling chamber through another gas phase section separated from the above-mentioned gas phase section in the upper part of the device main body, and then cooled with the cooling water, and then placed in a dish-shaped container. There have already been proposals for sending out the information outside the main body of the device.
However, in this continuous sterilization method, the dish-shaped containers that contain the objects to be sterilized and are stacked up and down in multiple tiers, the cooling water in the lower tier of the dish-shaped containers enters the gas phase later than the upper tier. It is introduced into the hot water, and after leaving the hot water, it exits into the gas phase and is first introduced into the cooling water, so that the upper dish-shaped container is the opposite of the lower dish-shaped container. For this reason, there is a difference in the heating sterilization time of the objects to be sterilized in the hot water stored in the upper and lower dish-shaped containers, and therefore there is also a difference in the F value indicating the degree of killing of microorganisms. In particular, in the case of high-temperature, short-time sterilization, such as at a sterilization temperature of 145 pm and a sterilization time of 2 minutes, the above-mentioned F value becomes an important issue. This invention makes it possible to sterilize objects to be sterilized at any position in dish-shaped containers stacked one above the other in the same time and under the same conditions, eliminates non-uniformity in F value, and enables good continuous sterilization. The purpose is to do so. In order to achieve this object, the present invention supplies a heating gas to either one of the gas phase parts in the apparatus main body in the continuous sterilization method described above, so that the object to be sterilized can be sterilized by heating with hot water. The gist is to heat sterilize under the same conditions as before.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an apparatus for carrying out the continuous sterilization method according to the present invention.

In Fig. 1, reference numeral 1 denotes the main body of the apparatus. A sterilization chamber 2 filled with hot water is formed in the main body 1 of the apparatus, and a box-shaped chamber wall 3 with an open upper surface is made of heat insulating material. It consists of
A cooling chamber 4 filled with cooling water is formed outside the chamber wall 3, and the lower end of a partition 10 provided on the inner surface of the upper wall of the apparatus main body 1 is immersed in hot water in the sterilization chamber 2. Gas phase portions 9a and 9b separated by a partition 10 are formed in the upper part of the apparatus main body 1. A transport conveyor 5 is provided in the main body 1 of the apparatus, and an endless chain 7 is hung around a large number of guide wheels 6, some of which also serve as drive sprockets, in a substantially concave shape on the side. A large number of objects to be sterilized 8 are rotatably suspended at predetermined intervals and are always maintained vertically. Hot water in chamber 2 - the other gas phase. 9b - The cooling water is circulated through the cooling water path of the cooling chamber 4. 11 is a casing 12 fixed to the right edge of the device body 1 next to a rotary valve type pressure breaker.
A rotor 13 is joined in a competitive manner, and a plurality of recesses 13a for objects to be sterilized are formed at equal intervals in the circumferential direction, and the rotor 13 has a forced ejection mechanism (not shown). ing.

A feeding means 14 is provided in the upper part between the transport conveyor 5 and the pressure breaker 11 in the apparatus main body 1, and a sending means 15 is provided in the lower part.
are arranged respectively. A water tank 16 is installed outside the pressure breaker 11, and a supply/discharge conveyor 17 is provided in the water tank 16 so that the side 11 of the pressure breaker is located below. An external feed mechanism 18 is provided in the upper part between the pressure breaker machine 11 and the supply/discharge conveyor 17, and an external feed mechanism 19 is provided in the lower part. Reference numeral 20 denotes a gas phase temperature control mechanism, in which temperature detection elements 21a and 21b are inserted into the gas phase portions 9a and 9b, and the temperature and pressure control mechanism is operated by inputting detection signals from these elements and incorporates a computing unit. A cooling air pipe 23 is installed in the gas phase part 9a on the right side, and supply pipes 24 and 25 for water vapor and pressurized air, and an exhaust pipe 2 are installed in the gas phase part 9b on the left side.
6 are connected to each other, and these pipes are connected to the control section 2.
Valves 27, 28, 29, and 30 which are opened and closed by signals from 2 are provided, respectively.

In addition, the conveyor 5, the rotor 1 next to the pressure breaker 11
3. The movable parts of the supply/discharge conveyor 17, the feed means 14, the feed means 15, the external feed mechanism 18, and the external feed machine 19 are driven periodically.

Further, hot water of 100 qo or more is introduced into the sterilization chamber 2, and cooling water is introduced into and discharged from the cooling chamber 4 and the water tank 16, respectively. FIGS. 2 and 3 show an example of a conveyor for a fan-flat flexible package.

This conveyance tool 31 includes a frame 33 in which a plurality of dish-shaped containers 32, each containing a plurality of partitioned and horizontally housed objects to be sterilized made of flexible packaging, are stacked and removably loaded in a plurality of upper and lower stages. Wheels 34 are rotatably provided on both end faces of this frame 33,
These wheels 34 are connected by a connecting rod 35, and a key 36 is fixed to the bottom of the frame 33, so that the dish-shaped container 32 is always held horizontally. Next, a method for continuous sterilization using the continuous sterilization apparatus shown in FIG. 1 and the conveyor shown in FIGS. 2 and 3 will be explained. Objects to be sterilized made of flat flexible packaging bodies are housed in a dish-shaped container 32, stacked vertically in a plurality of tiers, and loaded into a frame 33 of a transport odor 31. The transport tool 31 containing the objects to be sterilized in this way
is supplied to the supply/discharge conveyor 17, and this conveyor 17
, the conveyed odor 31 is transferred to the drum recess 1 provided in the rotor 13 next to the pressure breaker 11 via the external feeding mechanism 18.
Send it to 3a. By counterclockwise rotation of the rotor 13, the conveying tool 31 is guided into the apparatus main body 1, and is sent to the feeding means 14 by a forced ejection mechanism provided on the rotor 13, and then transported through the feeding means 14. It is sent to the object to be sterilized receiver 8 of the transport conveyor 5. The conveying tool 31 sent into the object receiver 8 transports the dish-shaped container 32 and the object to be sterilized horizontally and without falling over by the drive of the transporting Kosobear 5, and transports the object into the cooling water in the cooling chamber 4. The material is introduced into the hot water in the sterilization chamber 2 through the gas phase section 9a, and the object to be sterilized is heated and sterilized with this hot water, and then introduced into the cooling water in the cooling chamber 4 through the gas phase section 9b, and cooled with this cooling water. do. The transport tool 31 with the cooled object to be sterilized is received by the delivery means 15 from the object receiver 8, and the delivery means 1
5 into the empty iron fitting recess 13a of the rotor 13 of the pressure breaker 11. It should be noted that this iron fitting recess 13a is emptied by extruding a carrier containing objects to be sterilized before sterilization. The conveyance odor 31 after sterilization and cooling of the object to be sterilized that has been sent into the competition recess 13a is led out of the apparatus main body 1 by the rotation of the rotor 13, and is delivered to the external delivery mechanism 19 by the operation of the forced discharge mechanism of the rotor 13. External delivery mechanism 19
It is sent to the supply/discharge conveyor 17 by the operation of , and is discharged to a predetermined location by this conveyor 17. Then, the dish-shaped container is removed from the frame of the carrier, and the object to be sterilized is taken out from the dish-shaped container. The heating sterilization and cooling of the object to be sterilized has been described above with attention to one transport tool, but the heating sterilization and cooling described above are performed continuously for a large number of transport odors. As described above, the conveyor 5 always transports the dish-shaped containers and the objects to be sterilized in a horizontal state, so that the dishes containing the objects to be sterilized and stacked up and down in multiple stages are loaded into the transport tool 31. The lower plate-shaped containers 32 from the cooling water exit the gas phase section 9a later than the upper ones and are led into the hot water first, and the lower dish-shaped containers 32 from the hot water exit into the gas phase section 9b later from the hot water. It is led into the cooling water first, and therefore the lower dish-shaped container 32 remains in the hot water for a longer period of time than the upper one.

Therefore, water vapor and pressurized air are blown into the gas phase portion 9b on the side where the dish-shaped container 32 comes out of the hot water and is led into the cooling water from these supply pipes 24 and 25, and the gas phase portion is blown from the exhaust pipe 26. By discharging a part of the gas in 9b, the object to be sterilized accommodated in the dish-shaped container 32 is also heated and sterilized in the gas phase part 9b. In this heat sterilization, the temperature of the gas phase section 9b is detected by the temperature detection element 21b, and the temperature and pressure control section 22, the supply pipes 24, 25, and the valve 2 of the exhaust pipe 26 are detected by blocking this detection signal.
By outputting the signals 8, 29, and 30' and controlling their opening degrees, the temperature and pressure of the gas phase section 9b can be maintained at a predetermined state, and the object to be sterilized can be sterilized by heating with hot water. Heat sterilize under the same conditions as before. When heat sterilizing with hot water at 121℃, the conditions are 80% or more of water vapor and 20% air.
By heating in the gas phase section 9b using a mixture of 5% or less, the object to be sterilized can be sterilized by heating in the same manner as hot water.
Then, by successively heating and sterilizing the hot water in the sterilization chamber 2 and the steam and pressurized air in the gas phase section 9b, the lower dish-shaped containers 32 are exposed to the hot water before the upper ones, as described above. Since the cooling water first enters the gas phase section 9b, the four-shaped containers 32 loaded with the respective transport odors 31' are heated and sterilized for the same amount of time for both the upper and lower tiers.
After heat sterilization, it is immediately cooled with cooling water, so that heat sterilization is uniformly performed. In addition, the dish-shaped container 32
In the gas phase part 9a on the side where the gas comes out of the cooling water and is led into the hot water,
By supplying cooling air from the cooling air pipe 23, the objects to be sterilized are prevented from being heated in the gas phase section 9a, and this also prevents uneven heating between the upper tray-shaped container 32 and the lower tray-shaped container. In addition to preventing the gas phase part 9 due to aging,
Excessive heating and sterilization due to the rise in temperature of the gas inside a is suppressed.

Note that the temperature and pressure control of the gas phase portion 9a is also performed by the gas phase portion 9b.
This is done using almost the same machine as in the case of , and the gas phase section 9
It is preferable that an exhaust pipe having a valve is also provided in a to control the pressure in the gas phase portion 9a. In this invention, in the above-mentioned embodiment, cooling air is supplied to the gas phase where the cooling water enters the hot water, and water vapor and pressurized air are supplied to the gas phase where the hot water enters the cooling water. However, this may be reversed so that water vapor and pressurized air are supplied to the former gas phase, and cooling air is supplied to the latter gas phase.

Further, in the present invention, the heating gas supplied to the gas phase portion may be only water vapor, or room temperature air and sprayed cooling water may be supplied instead of cooling air.

Further, in the present invention, the conveyance speed of the object to be sterilized by the conveyor is changed to obtain a heat sterilization time that takes into account heat sterilization by heated gas in the gas phase.

As explained above, according to the present invention, a plurality of stacked dish-like containers containing objects to be sterilized made of flexible packaging bodies are stacked one above the other, and the dish-like containers are brought into a horizontal state by a conveyor. In the case where the object to be sterilized is heated and sterilized by being guided from the cooling water into the hot K through the gas phase section, and then guided to the cooling water through another gas phase section separated from the gas phase section for cooling, By supplying heated gas to either one of the gas phase parts and heat sterilizing the object under conditions substantially similar to heat sterilization with hot water, the object is stored in the upper layer of the stacked dish-shaped containers. The objects to be sterilized and the objects to be sterilized stored in the lower row are
Since sterilization is carried out under similar heat sterilization conditions, the F value can be made uniform, good continuous sterilization can be performed, and the effect is particularly suitable for high-temperature short-time sterilization.

[Brief explanation of the drawing]

Fig. 1 is a schematic side sectional view showing an example of a sterilizer for carrying out the continuous sterilization method according to the present invention, Fig. 2 is a front view showing an example of a carrier used in the continuous sterilization method according to the invention, and Fig. 3 is a side view of the same. It is. 1... Apparatus body, 2... Sterilization chamber, 4... Cooling room, 5... Transport conveyor, 9a, 9b...
Gas phase section, 10... Partition, 11... Pressure breaker, 20... Gas phase temperature control mechanism, 2
4, 25... Water vapor, pressurized air supply pipe, 26
…···Exhaust pipe. Figure 1 Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. A plurality of stacked dish-shaped containers made of flexible packaging containing objects to be sterilized are stacked up and down in multiple tiers, and are fed from outside the device main body to a conveyor provided inside the device main body, This conveyor transports the dish-shaped container while keeping it in a horizontal state, and guides it from the cooling water filled in the cooling chamber through the gas phase in the upper part of the device main body into the hot water filled in the sterilization chamber. After the object to be sterilized is heated and sterilized with water, it is introduced into the cooling water filled in the cooling chamber through another gas phase section separated from the above-mentioned gas phase section in the upper part of the main body of the device, and then cooled with the cooling water, and then placed in a dish-shaped container. In a continuous sterilization method in which the sterilization material is sent out of the apparatus main body, a heating gas is supplied to either one of the gas phase parts, and the object to be sterilized is heat sterilized under substantially the same conditions as heat sterilization with hot water. A continuous sterilization method characterized by: 2. Claim 1, in which the object to be sterilized is cooled by supplying a cooling fluid to the other gas phase part to which heating gas is not supplied.
Continuous sterilization method described in section.