JP2857763B2 - Pressure control method in retort sterilization of gas-filled cans - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure control method for retort sterilizing beverages and other foods and pharmaceuticals containing carbon dioxide, nitrogen gas or a mixture thereof.

2. Description of the Related Art Conventionally, when sterilizing gas-filled cans, a method has been adopted in which sterilization is performed with a pasteurizer (warm water shower type) under normal pressure, or sterilization is performed by reducing the acidity with carbon dioxide gas. No retort sterilization is currently performed on gas cans.

PROBLEM TO BE SOLVED BY THE INVENTION Sterilization by the pasteurizer of the above-mentioned hot water shower type is under normal pressure, so it has a long time, has difficulty in uniform treatment, and is not suitable for mass treatment.

Furthermore, in order to pursue lightweight and inexpensive cans for cans, the use of aluminum cans has been demanded from steel cans. Become.

In addition, sterilization under a pressure of 100 ° C or more is desired for canned foods and carbonated beverages, etc., which are filled under a positive pressure higher than normal pressure when filling cans. Can't respond to requests. Furthermore, there is a demand for retort sterilization of canned aluminum used in the field where steel is not used as a canned beverage or other foods or pharmaceuticals.

The object of the present invention is to solve the above-mentioned difficulties, predict the internal pressure of the can that enables retort sterilization, sterilize the can at the time of heat sterilization according to the internal pressure of the can, and sterilize at high pressure for a short time. An object of the present invention is to provide a pressure control method capable of processing.

Means for Solving the Problems In order to achieve the above object, the present invention retort sterilizes canned beverages and other foods containing one of carbon dioxide gas and nitrogen gas or a mixture of these gases, Filling pressure, filling temperature and filling rate are input as parameters to the calculation unit via the setting unit, and the internal pressure with respect to the sterilization temperature is obtained from the water dissolution volume curve of carbon dioxide gas, oxygen or air and the saturated steam curve, and this pressure and A pressure control method in the retort sterilization of gas-filled canned cans in which the internal pressure of the retort container was controlled by a pressure regulator so as to perform the sterilization treatment under the same or higher pressure.

Function In the present invention, data such as filling pressure, filling temperature and filling rate when a beverage or other food containing a carbon dioxide gas, a nitrogen gas or a mixed gas thereof is canned are input to a computing unit as parameters, The pressure value for preventing deformation when an aluminum can or the like is used as the can can be calculated by determining the internal pressure of the can at the sterilization temperature from the water dissolution volume curve of oxygen, oxygen or air, and the saturated water vapor pressure curve.
Therefore, by applying a pressure equal to or higher than this pressure value in the retort container, cans that can be easily deformed like aluminum can be treated with confidence.

FIG. 1 is a block diagram showing an apparatus for carrying out the method of the present invention.

Reference numeral 1 denotes a setting unit which inputs a carbon dioxide gas filling pressure, a nitrogen gas filling pressure, a filling temperature, and a filling rate to the arithmetic unit 4 as parameters. The input data is displayed on the display unit 5.

Reference numeral 2 denotes a pressure controller, a control signal, and an alarm signal oscillating unit. 3 is the retort sterilizer temperature, converter, A /
The signal is input to the arithmetic unit 4 via the D converter. In the calculation unit 4, a saturated vapor pressure curve and a water solubility curve of carbon dioxide, oxygen or air are input in advance in accordance with Henry's law or Charles' law, and the gas at the sterilization temperature is calculated by these rules. In addition, the expansion of water and the internal pressure of the can are predicted.

This predicted value is sent to the pressure controller 2 as a set value. The pressure controller compares the measured value with the set value and outputs a pressure signal or an air release signal from the pressure controller 8 to keep the pressure in the retort container equal to the pressure in the can. 6 is a pressure valve,
7 is an air vent valve.

As described above, in the method of the present invention, the prediction of the internal pressure of the can is easily calculated by inputting the conditions at the time of filling as a parameter, and the pressure inside and outside the can is adjusted by adjusting the pressure inside the retort container using this value as a set value. As a result, heat treatment can be carried out safely even for soft cans such as aluminum by equalizing the internal and external pressures regardless of the temperature rise during retort sterilization.

Effects of the Invention Since the present invention has the above-described configuration, during retort sterilization, it does not cause deformation during heating even for a flexible canned food such as aluminum, filling pressure during filling, filling temperature and The set pressure is automatically calculated simply by inputting the filling rate as a parameter to the calculation unit, and control is performed using this pressure, so that high temperature sterilization can be performed in a short time, and the effect is great.

[Brief description of the drawings]

The drawing is a block diagram showing an apparatus for implementing the method of the present invention. 1... Setting section, 4... Calculation section, 8... Pressure adjustment section

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) A23L 3/10

Claims (1)

(57) [Claims] When a canned beverage or other food containing one or a mixture of carbon dioxide gas and nitrogen gas is retorted, a filling pressure, a filling temperature and a filling rate of the gas are set as parameters. To calculate the internal pressure of the can with respect to the sterilization temperature from the water dissolution volume curve of carbon dioxide, oxygen or air and the saturated water vapor pressure curve, and sterilize at a pressure equal to or higher than this pressure. A pressure control method in retort sterilization of canned gas cans, wherein the internal pressure of the retort container is controlled by a pressure regulator.