JPH0753095B2 - Pressurizing method in spray sterilizer - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressurizing method in an apparatus for heat sterilizing a pouch food or an object to be heated such as a container under high temperature and high pressure such as a spray type sterilizer.

[0002]

2. Description of the Related Art Conventionally, a high temperature and high pressure sterilizer such as a retort sterilizer has been used for heat sterilization of pouch foods and the like. When heat sterilizing this pouch food or a heated object in a container, it is necessary to keep the temperature in the treatment tank at 100 ° C. or higher, and to prevent bag breakage or deformation of the pouch, etc. The principle of the conventional pressurizing method is to introduce pressurized air into the inside to raise the pressure and then raise the temperature of the circulating water.

[0003]

However, in order to pressurize the inside of the processing tank in advance as described above, it is necessary to introduce pressurized air into the processing tank, which consumes a large amount of compressed air. There is a problem that the load of the compressor becomes large, and particularly when an attempt is made to increase the size of the spray-type sterilizer to improve the processing scale, the compressor and other mechanical equipment become large and economically expensive.

The object of the present invention is to eliminate the above-mentioned problems and to make the pressure inside the treatment tank not forcedly raised by introducing a pressurized gas before heat sterilization, but to make the treatment tank closed. It is intended to provide a pressurizing method for increasing the internal pressure by increasing the temperature of the internal gas and water.

[0005]

In order to achieve the above object, the present invention has a plate type heat exchanger installed outside through a pipe in a treatment tank of a spray type sterilizer, and the treatment tank and the plate type heat exchanger. A pressure method was used in a spray sterilizer in which the temperature was raised by heating while forcibly circulating water between them, and the pressure was raised only by the water and gas circulating in the closed treatment tank.

[0006]

The water in the treatment tank circulates between the heat exchanger and the heat exchanger through the pipe, and the heat exchanger performs indirect heating. Since the treatment tank is completely sealed, it does not require pressurized air from the outside, and the internal pressure of the treatment tank can be increased by increasing the temperature of the water and gas (air, nitrogen gas, etc.) inside.
2Kg / cm2 required for heat sterilization of ordinary pouch foods
With Torr G, high temperature and high pressure of about 120 ° C was maintained and processing became possible.

[0007]

EXAMPLE A spray type sterilizer is loaded with an object to be treated in a treatment tank, hermetically sealed, and indirectly heated by spraying hot water from the side. The heated water is forcedly circulated between the processing tank and the plate heat exchanger via piping. When the temperature rises above the required temperature, a predetermined pressure is maintained, so the air vent valve is opened for adjustment.

FIG. 1 is a graph showing the state of pressure rise and temperature rise in the closed treatment tank of the method of the present invention, where the horizontal axis shows the time elapsed from the left, the left vertical axis shows the temperature, and the right side shows the pressure. FIG. 2 is a graph of a conventional example shown for comparison. Similarly, the horizontal axis shows time, the left vertical axis shows temperature, and the right side shows pressure. It was demonstrated that the method of the present invention enables heating by natural pressurization.

FIG. 3 is a sectional view showing the temperature rising and pressurizing state of the circulating water in the closed processing tank, 1 is a processing tank, 2 is a spray pipe, 3 is a heat exchanger, 4 is a pump, and 5 is an air vent valve. .

[0010]

As described above, according to the present invention, in the spray type sterilizer, it is not necessary to pressurize the circulating water in the treatment tank in advance, so the pressurization is required. Only the amount of air is saved, the load on the compressor can be reduced, and it has become possible to scale up to a large machine easily and economically. In addition, there is an effect that bags such as pouch food products do not break even by natural pressurization in the closed treatment tank.

[Brief description of drawings]

FIG. 1 is a graph of pressurizing and heating according to the method of the present invention.

FIG. 2 is a graph of pressurization and temperature rise of a conventional example.

FIG. 3 is a sectional view of a main part of a spray type sterilizer.

Claims (1)

[Claims] 1. A plate heat exchanger is installed externally through a pipe in a treatment tank of a spray type sterilizer, and heating and heating are performed while forcibly circulating water between the treatment tank and the plate heat exchanger, A pressurizing method in a spray type sterilizer characterized in that pressurization and temperature increase are carried out only with water and gas circulating in a closed treatment tank.