JP2779870B2 - Retort sterilizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a retort sterilizer,
More specifically, in a spray-type or shower-type retort sterilizer that performs control so as to change the pressure in a processing tank for performing pressurized heat sterilization in accordance with a change in the internal pressure of a sealed package to be processed. The present invention relates to a retort sterilizer that effectively prevents generation of sterilization unevenness.

[0002]

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

[0003] The shower-type retort sterilizer is provided with a shower plate having a large number of small holes uniformly provided above a tray stacked in a processing tank for performing pressure heat sterilization.
The retort sterilization treatment is performed by pouring hot water onto the package in a shower form from there (see JP-A-61-2).
60863, "FOOD PACKAGING" 19
July 1986, P120-P133). On the other hand, the spray-type retort sterilizer is provided with spray portions at the four corners of each stage of the laminated tray, sprays hot water from the spray portion in a fan shape, and pours it in a spray form onto a package placed on the tray. To perform a retort sterilization treatment (Japanese Utility Model Laid-Open No. 63-165195, Japanese Utility Model Laid-Open No. 64-19436,
Japanese Utility Model Application Laid-Open No. 64-19437 and Japanese Utility Model Application No. 64-19438
No., Japanese Utility Model Publication No. 64-20849). Such shower-type retort sterilizers and spray-type retort sterilizers have lower equipment costs and running costs than hot-water retort sterilizers, but have less heat sterilization unevenness than steam-type retort sterilizers, and have attracted attention. ing.

[0004]

SUMMARY OF THE INVENTION The present inventors use 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 a pressure heat sterilization treatment to a package (hereinafter, referred to as a sealed package).

[0005] First, the pressure in the treatment tank for pressurized heat sterilization was controlled so as to match the pressure change in the sealed package.

However, many of the hermetically sealed packages thus obtained have poor sterilization. That is, there is a problem that unevenness in heat sterilization occurs remarkably.

[0007]

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

In other words, when the sealed package is subjected to heat and pressure sterilization, the internal pressure of the sealed package constantly changes during sterilization, but especially at the time of temperature increase, that is, at a constant temperature from the start of heat sterilization. By the time you start, it changes abruptly. In order to prevent the breakage and deformation of the sealed package in response to such a sudden change in pressure inside the sealed package, a large amount of air must be blown in a short time to raise the pressure in the treatment tank correspondingly. It will be sent into the processing tank. The large amount of low-temperature air supplied in a 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 heat sterilization unevenness. I got the knowledge that I was sick.

Therefore, based on the above findings, the present inventor has conducted intensive research and development. As a result, the inner surfaces of both sides of a horizontal cylindrical processing tank for performing pressurized heat sterilization are made spherical.
Providing a plurality of air inlets for pressure adjustment along the longitudinal direction substantially horizontally or upwardly at the upper ends of both ends of the processing tank, and providing an air outlet for pressure adjustment at the upper center of the processing tank. As a result, it has been found that air introduced for pressure adjustment can be sufficiently diffused in the treatment tank, and the occurrence of heat sterilization unevenness can be effectively prevented.

The present invention has been completed on the basis of the above findings, and comprises a horizontal cylindrical processing tank containing therein a hermetically sealed package to be subjected to pressurized heat sterilization, and an upper and lower processing tank. A tray on which the hermetically sealed package is placed on which is stacked at intervals in the direction, a water supply port for spraying or showering hot water or cooling water onto the hermetically sealed package, and water collected at the bottom of the treatment tank And a circulation path for supplying water to the water supply unit again through the pump and the heat exchanger under pressure, and pressurized heat sterilization processing for controlling the pressure in the processing tank to change in accordance with the pressure change in the sealed package. In the retort sterilizer for, the inner surface of both sides of the processing tank is spherical, and at the upper end of both ends of the processing tank, a plurality of air inlets for pressure adjustment along the longitudinal direction are substantially horizontal or upward. At the center 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 the water vapor, so a part of the large amount and low temperature of the introduced air flows from the air inlet to the bottom along the spherical inner surface at the end of the processing tank. It descends and then flows from both ends along the lower part to the center, from where it rises towards the air outlet. Another portion of the introduced air descends from the air inlet to the bottom along the inner wall on the side of the processing tank, and then flows along the lower part to the center, where it rises toward the air outlet. As a result, the air in contact with the sealed package is sufficiently diffused and heated, and the amount of low-temperature air directly blown to some of the sealed packages can be significantly reduced. As a result, it is possible to prevent the temperature of some of the hermetically sealed packages from lowering, and effectively prevent the occurrence of heat sterilization unevenness.

That is, the air taken in during the pressurized heat sterilization treatment is sufficiently diffused in the treatment tank,
The occurrence of heat sterilization unevenness can be effectively prevented.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the contents of the present invention will be described in detail based on one embodiment.

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

In the drawing, reference numeral 1 denotes a retort sterilizer. The retort sterilizer 1 has a cylindrical horizontal processing tank 2 for performing pressure heat sterilization processing. In this processing tank 2, a plurality of trays 3 stacked vertically at intervals are arranged in a longitudinal direction. It is stored in a row. Further, small holes are formed in each tray 3 almost uniformly, and the sealed package 4 is placed almost evenly on each tray 3.

The inner surfaces of both ends 24 in the longitudinal direction of the processing tank 1 are spherical. At least one of the two ends 24 is a door that can be opened and closed, from which the stacked trays can be loaded and unloaded.

A spray section (water supply section) 6 is provided on the inner side surface of the processing tank 2 (see FIG. 2). The spray unit 6 includes 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, 9 respectively
b, 9c. Further, the spray nozzles 7 are vertically arranged at the four corners of the trays 3 of the respective stages in accordance with the intervals between the trays 3, and can spray hot water and cooling water in a fan shape, respectively. as a result,
The hot water and the cooling water sprayed from the spray nozzle 7 are sprayed and poured onto the sealed package 4 on the tray 3.

The water discharge pipe 1 is provided at the bottom 14 of the treatment tank 2.
5 is disposed, and the water discharge pipe 15 communicates with the water supply pipe 9 via a pump 16 and a heat exchanger 17 to form a circulation path. The heat exchanger 17 is also connected to 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 connected via a valve 15a.
Is provided, from which water in the treatment tank 2 can be discharged.

An air introduction pipe 19 is provided in the upper part of the processing tank 2 in the longitudinal direction (see FIG. 1). A plurality of air introduction pipes are provided in the upper part of both ends of the air introduction pipe 19 in the longitudinal direction. Inlets 20 are provided at equal 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 against 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 tank 2 via an air supply pipe 21.

Further, an air outlet 22 is provided at the upper center of the processing tank 2, and an open / close valve (not shown) is provided at the air outlet 22.

In the retort sterilizer 1, the temperature in the processing tank 2 during the pressurized heat sterilization process is controlled so as to match a preset temperature change pattern. The sealed package 4 when the pressure in the inside is subjected to the pressurized heat sterilization treatment based on the temperature change pattern.
Is controlled so as to match a predetermined pressure change pattern in the processing tank so as to prevent the bag from being broken or deformed.

The above-mentioned temperature control is desirably performed by controlling the supply and discharge amounts of hot water and cooling water.

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

Next, a method of pressurizing and heating sterilization 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 carried in therefrom. Thereafter, 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 the hot water is controlled so as to match the preset temperature change pattern.

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

After pressurized heat sterilization 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 processing tank 2 used for spraying is gradually cooled.

Finally, the circulated 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,
After the temperature of the water in the circulation path is lowered to some extent, the cooling water can be directly supplied to the spray section 6.

When the cooling water is supplied directly from the circulation path to the spray section 6, the water in the processing tank 2 may 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 well-known pressure detecting means (not shown). Then, based on the obtained pressure value, the pressure inside the processing tank 2 is determined based on the above-mentioned temperature change pattern to prevent the sealed package 4 from breaking or deforming. The supply of air into the processing tank 2 and the discharge of air from the air outlet 22 (opening and closing of the on-off valve) are controlled so as to match the pattern.

In this case, the inner surfaces of both sides 24 of the processing tank 2 are spherical, and a plurality of air inlets 20 are provided substantially horizontally or vertically above the both ends 24 of the processing tank 2 along the longitudinal direction. Since it is provided upward and the air discharge port 22 is provided at the upper center of the processing tank 2, the introduced air is sufficiently diffused into the processing tank 2 (particularly at the time of temperature rise). . That is, since the air is heavier than the water vapor, a part of the large amount and low temperature of the 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. Thereafter, the air flows from both ends 24 to the center along the lower part, and then rises toward the air discharge port 22. Another part of the introduced air descends from the air inlet 20 to the bottom along the inner wall of the side surface of the processing tank, and then flows to the center along the lower part, and then rises toward the air outlet 20. As a result, the air in contact with the sealed package 4 is sufficiently diffused and heated, and the amount of low-temperature air blown directly to some of the sealed packages 4 can be significantly reduced.
This prevents the temperature of some of the sealed packages 4 from dropping,
The occurrence of heat sterilization unevenness can be effectively prevented.

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

Another embodiment of the present invention is a retort in which, instead of the spray unit, a shower plate having uniformly arranged small holes above the stacked trays and a shower unit comprising a water inlet tube are provided. There is a sterilizer.

[0036]

[Brief description of the drawings]

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

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Retort sterilizer 2 Processing 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 Reference Signs List 20 air inlet 21 air supply pipe 22 air outlet 24 end of processing tank

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshiaki Tokuda 1-5-7 Mikitei-Sakaecho, Higashiosaka-shi, Osaka House Foods Industry Co., Ltd. 5-7 House Food Industry Co., Ltd. (72) Shozo Kanno 1-chome, Mitsuki Sakaecho, Higashiosaka-shi, Osaka 1-5-7 House Food Industry Co., Ltd. 1-5-7 House Food Industry Co., Ltd. (58) Field surveyed (Int.Cl. ⁶ , DB name) A61L 2/04 A23L 3/10

Claims (1)

(57) [Claims] 1. A horizontal cylindrical processing tank for accommodating a sealed package to be subjected to a pressure heat sterilization treatment, and a vertically sealed upper laminated package in the processing tank. , A water supply port for spraying hot water or cooling water onto the sealed package in a spray or shower form, and water collected at the bottom of the treatment tank through a pump and a heat exchanger under pressure again. In a retort sterilizer for pressurized heat sterilization, comprising a circulation path for supplying to the water supply unit, and controlling the pressure in the treatment tank to change in accordance with the pressure change in the sealed package. The inner surfaces of both sides of the processing tank are made spherical, and a plurality of air inlets for adjusting pressure are provided substantially horizontally or upward along the longitudinal direction at both ends of the processing tank. For pressure adjustment in the upper center of the tank A retort sterilizer, comprising: