JPH05309125A - Retort sterilizing device - Google Patents

Abstract

PURPOSE:To effectively prevent the occurrence of unevenness of heating and sterilization in a retort sterilizing device for carrying out pressurized heating sterilization. CONSTITUTION:In a retort sterilizing device 1 for carrying out pressurized heating sterilization, the inner surfaces of both end parts of a treatment tank 2 are formed in a spherical shape, and also on the upper parts at both end parts of the treatment tank, a plurality of air-introducing ports 20 for regulating the pressure are provided nearly horizontally and upwards in the longitudinal direction, and also an air discharge port 22 for regulating pressure is provided to the central upper part of the treatment tank. Thereby, a part of introduced air flows downward from the introducing ports to the bottom along the spherical inner surfaces of the treatment tank, and then flows from both the end parts to the central part along the bottom, and therefrom rises toward the air discharge port. Another part of introduced air flows downward from the air introducing ports to the bottom along the side inner walls of the treatment tank, and then flows toward the central part along the bottom, and therefrom rises toward the air discharge port. As a result, the air being in contact with the sealedly enveloped bodies is sufficiently diffused and heated.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a retort sterilizer.
More specifically, heating in a spray-type or shower-type retort sterilizer that controls so that the pressure in the treatment tank for pressure heat sterilization treatment is changed according to the change in the internal pressure of the sealed package to be treated. The present invention relates to a retort sterilizer that effectively prevents the occurrence of sterilization unevenness.

[0002]

2. Description of the Related Art Conventionally, hot water type retort sterilizers and steam type retort sterilizers have been known as retort sterilizers, and recently, shower type retort sterilizers and spray type retort sterilizers have been developed.

The shower-type retort sterilizer has a shower plate having a large number of small holes evenly arranged above a tray stacked in a treatment tank for pressure heat sterilization.
The retort sterilization process is performed by pouring hot water into the package in a shower shape from there (Japanese Patent Laid-Open No. 61-2).
No. 60863, "FOOD PACKAGING" 19
July 1986 issue, P120-P133). On the other hand, the spray-type retort sterilizer has spray parts at four corners of each layer of stacked trays, and sprays hot water from the spray parts into a fan shape and pours it in a spray form onto a package placed on the tray. The retort sterilization treatment is carried out according to the method (Actual No. 63-165195, No. 64-19436).
No. 64-19437, No. 64-19438
No., No. SHO 64-20849). These shower-type retort sterilizers and spray-type retort sterilizers have lower equipment costs and running costs than hot-water retort sterilizers, while they have less uneven heating sterilization than steam-type retort sterilizers, and are attracting attention. ing.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The inventors of the present invention have used the above-mentioned shower type retort sterilizer and spray type retort sterilizer to seal bags, containers and the like containing gas such as air and inert gas. An attempt was made to apply pressure heat sterilization treatment to a package (hereinafter referred to as a hermetically sealed package).

First, the pressure in the treatment tank for pressure heat sterilization was controlled so as to match the pressure change in the sealed package.

However, many of the hermetically sealed packages thus obtained were poorly sterilized. That is, there is a problem that heat sterilization unevenness is significantly generated.

[0007]

[Means for Solving the Problems] Therefore, the present inventors have conducted extensive studies to solve the above-mentioned problems, and have obtained the following findings.

That is, when the sealed package is heat-sterilized under pressure, the pressure inside the sealed package constantly changes during sterilization, but especially when the temperature is raised, that is, at the constant temperature from the start of the heat-sterilization process. By the time you start, it changes rapidly. In order to prevent bag breakage and deformation of the hermetically sealed package against sudden changes in pressure inside the hermetically sealed package, a large amount of air should be supplied in a short time in order to increase the pressure in the processing tank correspondingly. It will be sent into the processing tank. The large amount of low temperature air supplied in this short time is not sufficiently diffused in the treatment tank, and as a result, only a part of the sealed package is cooled by this air, which causes uneven heating and sterilization. I got the knowledge that it was sore.

Therefore, as a result of earnest research and development based on the above findings, the present inventor has made the inner surfaces of both sides of a horizontal cylindrical processing tank for pressure heat sterilization treatment spherical.
Provide a plurality of air inlets for adjusting the pressure in the upper part of both ends of the processing tank in a substantially horizontal or upward direction along the longitudinal direction, and provide an air outlet for adjusting the pressure in the central upper part of the processing tank. It was found that the air taken in for pressure adjustment can be sufficiently diffused in the treatment tank, and the occurrence of uneven heating sterilization can be effectively prevented.

The present invention has been completed on the basis of the above findings, and a horizontal cylindrical processing tank for accommodating a hermetically sealed package body to be subjected to heat sterilization under pressure and an upper and lower inside of the processing tank. A tray on which a sealed package is placed on top of each other with a space in between, a water supply port for spraying hot water or cooling water into the sealed package in a spray or shower form, and water collected at the bottom of the treatment tank. A heating and sterilization process for controlling the pressure in the treatment tank so as to change in accordance with the pressure change in the sealed package, and a circulation line for supplying the water to the water supply unit again through a pump and a heat exchanger under pressure. In the retort sterilizer for, the inner surface of both sides of the treatment tank is made spherical, and at the upper end of both ends of the treatment tank, air inlets for adjusting a plurality of pressures along the longitudinal direction are almost horizontal or upward. Installed in the upper part of the processing tank. Providing an air outlet for adjusting, it is retort sterilizer according to claim.

[0011]

[Operation and effect] Especially when the temperature is raised, the introduced air is heavier than water vapor, so a part of a large amount of low-temperature introduced air flows from the air inlet to the bottom along the spherical inner surface of the end of the processing tank. It then descends, then flows from both ends along the bottom to the middle, and then rises toward the air outlet. Another part of the introduced air descends from the air introduction port to the bottom along the inner wall of the side surface of the treatment tank, and then flows to the center along the lower part and rises from there toward the air discharge port. As a result, the air in contact with the hermetically sealed package is sufficiently diffused and heated, and the amount of low-temperature air blown directly to some hermetically sealed packages can be significantly reduced. As a result, it is possible to prevent the temperature of a part of the hermetically sealed package from lowering and to effectively prevent the occurrence of heat sterilization unevenness.

That is, the air taken in during the sterilization treatment under pressure is sufficiently diffused in the treatment tank.
It is possible to effectively prevent the occurrence of heat sterilization unevenness.

[0013]

The contents of the present invention will be described in detail below with reference to an embodiment.

FIG. 1 is a longitudinal sectional view in the longitudinal direction of a retort sterilizer according to an embodiment of the present invention, and FIG. 2 is a side sectional explanatory view of the retort sterilizer in a direction orthogonal to FIG.

Reference numeral 1 in the figure represents a retort sterilizer. The retort sterilizer 1 has a cylindrical horizontal type treatment tank 2 for performing a pressure heat sterilization treatment. In the treatment tank 2, a plurality of trays 3 stacked at intervals in the vertical direction are arranged in the longitudinal direction. They are stored in a line. Further, small holes are formed in each of the trays 3 almost uniformly, and the hermetically-sealed package 4 is placed on each of the trays 3 almost uniformly.

The inner surfaces of both end portions 24 in the lengthwise direction of the processing tank 1 are spherical. Further, at least one of the both end portions 24 is a door portion that can be opened and closed so that the stacked trays can be loaded and unloaded.

A spray section (water supply section) 6 is disposed on the inner side surface of the processing tank 2 (see FIG. 2). The spray unit 6 is composed of a spray nozzle 7 and a header pipe 8 extending in a substantially vertical direction for mounting the spray nozzle 7. The header pipe 8 is connected to a hot water supply source 10 and a cooling water supply source 11 by a water supply pipe 9. Valves 9a and 9 respectively
It is connected via b and 9c. The spray nozzles 7 are vertically arranged at the four corners of the trays 3 at the respective stages in accordance with the intervals between the trays 3, and can spray hot water and cooling water in a fan shape. as a result,
The hot water and the cooling water sprayed from the spray nozzle 7 are poured into the sealed package 4 on the tray 3 in a spray form.

The water discharge pipe 1 is provided at the bottom 14 of the treatment tank 2.
5, the water discharge pipe 15 communicates with the water supply pipe 9 via the pump 16 and the heat exchanger 17, and forms a circulation path. The heat exchanger 17 communicates with both the hot water supply source 10 and the cooling water supply source 11 via valves 9b and 9c.

On the discharge side (upper side in the figure) of the pump 16 of the water discharge pipe 15, a bypass pipe 25 is provided via a valve 15a.
Is provided, from which water in the treatment tank 2 can be discharged.

Further, an air introducing pipe 19 is arranged in the longitudinal direction at the upper part of the processing tank 2 (see FIG. 1), and a plurality of air is arranged at the upper ends of the air introducing pipe 19 along the longitudinal direction. The inlets 20 are provided at even intervals. The direction of the air inlet 20 is substantially horizontal or upward so that the air is not directly blown onto the sealed package 4 on the tray 3. That is, the air introduced from the inlet 20 is blown onto the inner wall 23 of the processing tank 2. The air introduction pipe 19 is connected to a pressurized air supply source (not shown) outside the processing bath 2 via an air supply pipe 21.

An air outlet 22 is provided at the upper center of the processing tank 2, and an opening / closing valve (not shown) is provided at the air outlet 22.

In the retort sterilizer 1, the temperature inside the treatment tank 2 during the pressure heat sterilization process is controlled so as to match the preset temperature change pattern, and the treatment tank during the pressure heat sterilization process is controlled. The sealed package 4 in the case where the internal pressure is subjected to pressure heat sterilization treatment based on the temperature change pattern.
The bag is controlled so as to match a predetermined pressure change pattern in the processing tank so as to prevent bag breakage and deformation.

The above temperature control is preferably performed by controlling the supply amount and discharge amount of hot water and cooling water.

The above-mentioned pressure control is performed by introducing air from a supply source of pressurized air into the processing tank 2 based on a detection result of a pressure detecting means (not shown) in the processing tank 1 and by processing the tank. It is performed by controlling the discharge of the air in 2 from the air discharge port 22 (opening / closing of the open / close valve).

Next, the method of heat sterilization under pressure by the retort sterilizer will be described.

First, the door at one end of the processing tank 2 is opened, and the stacked trays 3 are loaded from there. Then, the door is closed and the processing tank 2 is sealed.

Next, the supply of hot water from the hot water supply source 10 into the processing tank 2 is started. In this case, the supply of hot water is controlled so as to match the preset temperature change pattern.

The hot water supplied is sprayed in a fan shape from the spray nozzle 7 through the water supply pipe 9 and the header pipe 8. As a result, the sprayed hot water is sprayed onto the sealed packages 4 on the trays 3 of the respective stages, and the sealed packages 4 are sterilized by heating. The poured hot water then drops from the tray 3 and collects in the bottom portion 14 of the processing tank 2. The accumulated water is discharged from the treatment tank 2 through the water discharge pipe 15. Then, it is sent to the heat exchanger 17 by the pump 16, reheated there, and then returned to the water supply pipe 9 again.

After heat sterilization under pressure for a predetermined time, cooling water is supplied as a heat source of the heat exchanger 17 instead of hot water, and the hot water in the treatment tank 2 used for spraying is gradually cooled.

Finally, the circulating hot water is indirectly cooled by the heat exchanger 17, and water higher than the cooling water by about 3 to 5 ° C. is sprayed in the treatment tank 2. Also, if necessary,
The cooling water may be directly supplied to the spray unit 6 after the temperature of the water in the circulation path is lowered to some extent.

When the cooling water is directly supplied from the circulation path to the spray section 6, the water in the processing tank 2 can be discharged from the bypass pipe 25 on the discharge side of the pump so that the liquid level in the processing tank does not rise. preferable.

On the other hand, at the same time when the supply of hot water is started, the pressure inside the processing tank 2 is detected by a well-known pressure detecting means (not shown). Then, based on the obtained pressure value, the internal pressure of the processing tank 2 is changed based on the above-mentioned temperature change pattern so that the sealed package 4 can be prevented from being broken or deformed. The supply of air into the processing tank 2 and the discharge of air from the air outlet 22 (opening / closing of the open / close valve) are controlled so as to match the pattern.

In this case, the inner surfaces of both side portions 24 of the treatment tank 2 are spherical, and a plurality of air inlets 20 are substantially horizontal in the longitudinal direction above the both end portions 24 of the treatment tank 2. Since the air outlet 22 is provided upward and the air outlet 22 is provided in the upper center part of the processing tank 2, the introduced air is sufficiently diffused in the processing tank 2 (especially when the temperature is raised). .. That is, since air is heavier than water vapor, a part of a large amount of low-temperature introduced air descends from the air inlet 20 to the bottom 14 along the spherical inner surface of the end 24 of the processing tank 2 having a sufficient space. Then, it flows from both end portions 24 along the lower portion to the central portion, and then rises toward the air outlet 22. Another part of the introduced air descends from the air introduction port 20 to the bottom along the inner wall of the side surface of the processing tank, then flows to the center along the lower part and rises from there toward the air discharge port 20. As a result, the air in contact with the hermetically sealed package 4 is sufficiently diffused and heated, and the amount of low-temperature air directly blown to some hermetically sealed packages 4 can be significantly reduced.
This prevents the temperature of some of the sealed packages 4 from decreasing,
It is possible to effectively prevent the occurrence of heat sterilization unevenness.

Next, after the heat sterilization is completed, the door is opened and the stacked trays 3 are carried out from there.

In another embodiment of the present invention, instead of the spray section, a retort in which a shower section having a shower plate in which small holes are uniformly provided above the stacked trays and a water introducing pipe is arranged is arranged. There is a sterilizer.

[0036]

[Brief description of drawings]

FIG. 1 is a longitudinal cross-sectional view in a longitudinal direction of a retort sterilizer according to an embodiment of the present invention,

2 is a side cross-sectional explanatory view of the retort sterilizer in a direction orthogonal to FIG.

[Explanation of symbols]

 1 Retort sterilizer 2 Treatment tank 3 Tray 4 Sealed package 6 Spray part 7 Spray nozzle 8 Header pipe 9 Water supply pipe 10 Hot water supply source 11 Cooling water supply source 15 Water discharge pipe 16 Pump 17 Heat exchanger 19 Air introduction pipe 20 Air Inlet 21 Air Supply Pipe 22 Air Outlet 24 End of Processing Tank

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiaki Tokuda 1-5-7 Mikitei-cho, Higashiosaka-shi, Osaka House Food Industry Co., Ltd. (72) Inventor Ryusuke Nakanaga 1-chome, Mikitei-cho, Higashi-Osaka, Osaka House No. 5-7 House Food Industry Co., Ltd. (72) Shozo Kanno 1-5-7 Mikitei-cho, Higashi-Osaka City, Osaka Prefecture House House Food Industry Co., Ltd. (72) Michio Kurokawa Mitsuei-cho, East Osaka City Osaka Prefecture 1-5-7 House Food Industry Co., Ltd.

Claims (1)

[Claims] 1. A horizontal cylindrical processing tank for accommodating a hermetically sealed package to be subjected to a pressure heat sterilization process, and a hermetically sealed package which is laminated in the processing tank at intervals in the vertical direction. , A water supply port for spraying hot water or cooling water into the hermetically sealed package in the form of spray or shower, and water accumulated at the bottom of the treatment tank under pressure through a pump and a heat exchanger again. In a retort sterilizer for pressurizing heat sterilization treatment, which comprises a circulation path for supplying to the water supply unit, and controls so that the pressure in the treatment tank is changed according to the pressure change in the sealed package. The inner surfaces of both sides of the treatment tank are spherical, and at the upper ends of both ends of the treatment tank, a plurality of air inlets for adjusting pressure are provided substantially horizontally or upward along the longitudinal direction, and the treatment is further performed. For pressure adjustment in the upper center of the tank A retort sterilizer equipped with an air outlet.