JPH04304867A - Pressure method in spray sterilizer - Google Patents

Abstract

PURPOSE:To regulate the interior of a hermetically sealed treating vessel to >=100 deg.C temperature and a pressurized state by increasing temperature of circulating water without previously introducing pressurized air and pressurizing the interior. CONSTITUTION:A method for pressurizing by connecting a hermetically sealed treating vessel through a pipe to a plate type heat exchanger, heating circulating water and increasing the temperature while forcibly circulating the circulating water and pressurizing the interior of the hermetically sealed treating vessel only with the circulating water and gases.

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 a device such as a spray sterilizer that heat-sterilizes food products in pouches and containers under high temperature and pressure.

0002

BACKGROUND OF THE INVENTION Conventionally, high-temperature, high-pressure sterilizers such as retort sterilizers have been used for heat sterilization of pouched foods and the like. When heat sterilizing pouched foods or heated objects in containers, it is necessary to raise the temperature inside the processing tank to 100°C or higher and to prevent the pouches from breaking or deforming. The principle of conventional pressurization methods was to introduce pressurized air into the tank to increase the pressure and then raise the temperature of the circulating water.

0003

[Problems to be Solved by the Invention] 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, and the consumption of this pressurized air is large. The load on the compressor increases, and especially when trying to increase the scale of the treatment by increasing the size of the spray sterilizer, there are problems such as the compressor and other mechanical equipment becoming larger and becoming more expensive from an economic standpoint.

An object of the present invention is to solve the above-mentioned problems, and instead of forcibly increasing the pressure inside the processing tank by introducing pressurized gas before heat sterilization, the processing tank is kept in a closed state. The present invention aims to provide a pressurization method that increases internal pressure by increasing the temperature of internal gas and water.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention installs a plate heat exchanger externally through piping to the processing tank of a spray sterilizer, and connects the processing tank and the plate heat exchanger. The pressurization method used in the spray-type sterilizer is to heat and raise the temperature while forcing water to circulate between the tanks, and pressurize and raise the temperature using only the water and gas circulating in the sealed treatment tank.

[0006]

[Operation] Water in the treatment tank is circulated between the heat exchanger and the heat exchanger via piping, and indirect heating is performed by the heat exchanger. Since the processing tank is completely sealed, there is no need for pressurized air from the outside, and the internal pressure of the processing tank can be increased by increasing the temperature of the water and gas (air, nitrogen gas, etc.) inside.
It has become possible to maintain high temperature and high pressure of about 120° C. with 2 kg/cm2 G required for heat sterilization of ordinary pouched foods.

[0007]

[Embodiment] In a spray type sterilizer, objects to be processed are loaded into a processing tank, sealed, and hot water is sprayed from the side to perform indirect heat treatment. Heated water is forced to circulate between the treatment tank and the plate heat exchanger via piping. Additionally, when the temperature rises above the required level, open the air vent valve to maintain the predetermined pressure.

FIG. 1 is a graph showing the state of pressure rise and temperature rise in a closed processing tank according to the method of the present invention, in which the horizontal axis shows time elapsed from the left, the left vertical axis shows temperature, and the right shows pressure. FIG. 2 is a graph of a conventional example shown for comparison, and similarly shows time on the horizontal axis, temperature on the left vertical axis, and pressure on the right. It was demonstrated that heating by natural pressure increase is possible using the method of the present invention.

FIG. 3 is a cross-sectional view showing the heating and pressurizing state of circulating water in a closed treatment tank, where 1 shows the treatment tank, 2 shows the spray pipe, 3 shows the heat exchanger, 4 shows the pump, and 5 shows the air vent valve. .

0010

[Effects of the Invention] As described above, the present invention eliminates the need to pressurize the inside of the treatment tank before raising the temperature of the circulating water in the treatment tank in the spray-type sterilizer. This saves air and reduces the load on the compressor, making it possible to scale up to larger machines easily and economically. Furthermore, it has the effect that products such as pouched foods do not break due to the natural pressure increase in the sealed treatment tank.

[Brief explanation of drawings]

[Figure 1] Graph of pressurization and temperature increase using the method of the present invention

[Figure 2
] Conventional pressurization and temperature rise graph

Claims (1)

[Claims] 1. A plate heat exchanger is installed externally through piping to a treatment tank of a spray sterilizer, and water is heated and heated while being forcedly circulated between the treatment tank and the plate heat exchanger, A pressurization method for a spray-type sterilizer characterized by pressurizing and heating only water and gas circulating in a sealed treatment tank.