Pressure-controlling method of sterilizing kettle in sterilization cooling stage

Abstract

The invention discloses a sterilizing method by adopting a sterilizing kettle, particularly to pressure-controlling method of a sterilizing kettle in sterilization cooling stage, which comprises the following steps of: introducing high-pressure air into the sterilizing tank until the pressure therein reaches the initial value; introducing cooling water into the sterilizing tank until the water level therein reaches the set value; introducing compressed air into the sterilizing tank continuously, opening a circulation pump at intervals according to the pressure in the sterilizing tank, wherein when the pressure in the sterilizing tank is greater than the set value, the circulation pump is opened, and when the pressure in the sterilizing tank is less than the set value, the circulation pump is stopped; when the cooling process is completed, emptying the cooling water, and reducing the sterilizing pressure in the tank to atmospheric pressure. By continuously air-intaking and opening, the pressure in the sterilizing tank can be continuously compensated; the circulation pump is opened at intervals according to the pressure in the sterilizing tank, the cooling operation can be conducted in the premise of ensuring the pressure in the tank, therefore great pressure drop occuring at the moment when the pump is opened for intruductino fo the cooling water and in the temperature dropping process can be effectively prevented. The method can be suitable for the sterilization operations of cans, flexible packages and other types of packaged food.

Description

technical field [0001] The invention relates to a method for sterilizing by using a sterilizer, in particular to a pressure control method in the sterilizing and cooling stage of the sterilizer. Background technique [0002] The sterilizer uses steam with a certain pressure as the heat source, which has the characteristics of large heating area, high thermal efficiency, uniform heating, short boiling time of liquid material, and easy control of heating temperature. It is composed of a sterilization tank, a sterilization tank cover, a track, a sterilization basket and a number of nozzles, equipped with a pressure gauge and a safety valve. It is beautiful in appearance, easy to install, easy to operate, safe and reliable. It is widely used in the field of flexible packaging food. [0003] The sterilization process includes a heating stage, a constant temperature stage, and a cooling stage. In the cooling stage, in addition to controlling the temperature, it is also necessary...

AI Technical Summary

Problems solved by technology

But at the moment when the circulating pump is turned on, due to the increase in temperature difference between gas and liquid, the heat exchange area increases, the heat exchange efficiency increases greatly, and the pressure drop in the sterilization tank is large instantaneously, which can be reduced from 0.25MPa to 0.13MPa Regardless of whether manual, semi-automatic or automatic control methods are used to supplement the pressure in the sterilizer by injecting high-pressure air before the circulation pump is turned on, the pressure drop formed at the moment the circulation pump is turned on cannot be compensated, and the bag burst rate of plastic flexible packaging products is relatively high. , so the existing sterilizers are suitable for narrow product series, which seriously limits its application in the field of plastic soft packaging food