JPS6024698B2 - How to replace the atmosphere inside the refrigerator - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for replacing the atmosphere inside a refrigerator or the like.

When storing fruits and vegetables, the freshness of the fruits and vegetables is determined as the more the fruits and vegetables themselves have a strong respiration effect, the faster they ripen and the faster their freshness deteriorates.

In order to suppress this respiration effect and maintain freshness over a long period of time, conventional methods have been used to maintain the atmosphere (usually air) at a low temperature, and gradually the air is replaced with nitrogen gas to reduce the nitrogen gas atmosphere. I've started using it.
When nitrogen gas is used, conventionally the nitrogen gas has been filled by simply introducing nitrogen gas into the refrigerator from one side and simultaneously exhausting the air inside the refrigerator from the other side.
According to such a filling method, efficient replacement cannot be performed,
Generally, it is said that the amount of nitrogen gas required to lower the oxygen concentration in the refrigerator to about 2 to 3% is required to be about 2 to 3 times the volume of the refrigerator. However, nitrogen gas is expensive, and it was desired to replace the air in the refrigerator as efficiently as possible to reduce the oxygen concentration in the refrigerator by 4.

In view of such circumstances, it is an object of the present invention to provide an atmosphere replacement method that enables efficient replacement using a simple device.

For this reason, the present invention utilizes a slight pressure difference to form a layer of nitrogen gas along the inner wall surface of the refrigerator in order to minimize the disturbance of the air inside the refrigerator when nitrogen gas is introduced into the refrigerator. It is characterized in that nitrogen gas is introduced into the refrigerator so as to grow this layer as a whole, and the air inside the refrigerator is discharged from the center of the refrigerator.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following description will be made with reference to the drawings showing an apparatus in which the present invention can be implemented.

As shown in FIGS. 1 and 2, this refrigerator 1 has a perforated wall cloth 2 stretched along the top and side surfaces of its inner wall at small intervals d of, for example, several centimeters. There is.

This hazel cloth 2 is made of, for example, woven synthetic resin fibers, and it is desirable that the weave is so fine that it has slight air permeability. Of course, although not shown in the drawings, a suitable wicker cloth support material is used, but here the space 3 given by the distance d between the monkey cloth 2 and the inner wall top surface and the inner wall side surface is isolated by the monkey cloth support material. There is no such thing as speed. Nitrogen gas inlet openings 4A and 4B are formed at two locations along one of the upright edges of the side wall of the refrigerator 1.

The inlet openings 4A, 4B are connected to a nitrogen gas supply tank (not shown) by suitable piping (not shown). In addition, in order to exhaust the air inside the refrigerator at the same time as nitrogen gas filling,
A duct 5 is suspended through the upper wall of the refrigerator 1. This duct 5 has a fan 6 inside, and is positioned so that its lower end opens at the center of the refrigerator. Of course, such a duct 5 may be removed after filling with nitrogen gas and its insertion port and feed openings 4A, 4B may be sealed, or the duct 5 and feed closing ports 4A, 4 may be left as they are even after filling is completed.
It should be selected as appropriate, such as sealing B, or using the inlet ports 4A, 4B and the duct 5 as a communication port for an external atmosphere cooling device. In such a structure, filling with nitrogen gas is performed as follows. In other words, nitrogen gas is fed into the space 3 partitioned by the bamboo cloth 2 through the feed openings ○4A and 4B. At the same time, the fan 6 is driven to exhaust air from the center of the refrigerator.
What is important at this time is that, as a feature of the present invention, the nitrogen gas is supplied so that the nitrogen gas pressure in the space 3 is maintained at a level slightly higher than the pressure of the air inside the refrigerator across the pipe cloth 2. It is to enter. Of course, this feeding amount varies depending on the fineness of the mesh of the monkey cloth 2. When the nitrogen gas is supplied into the space 3 in this manner, the nitrogen gas passes through the bamboo cloth 2 and flows into the refrigerator due to the pressure difference.

At this time, since the woven cloth 2 has a fine mesh and the pressure difference is 4 mm, this inflow is carried out very quietly and evenly from the entire surface of the woven cloth 2. Therefore, a layer 7 of nitrogen gas is formed along the inner surface of the monkey cloth 2, and this layer 7 develops to gradually increase in thickness. At the same time, the air inside the refrigerator is discharged from the duct 6 to the outside in an amount corresponding to the amount of nitrogen gas flowing in. At this time, since the masses of nitrogen and air are not much different, disturbances due to mass differences do not pose much of a problem. After determining the completion of nitrogen filling by appropriate means, such as by detecting the amount of air or nitrogen in the exhaust gas from the duct, the supply of nitrogen is stopped and the refrigerator 1 is sealed. As explained below, according to the present invention, nitrogen is fed into the refrigerator while developing a layer of nitrogen using a slight pressure difference, so collapsing with the air in the refrigerator is suppressed as much as possible. Efficient atmosphere replacement (the amount of nitrogen required can be reduced to about half compared to conventional methods) can be achieved, and cost savings can be achieved to a great extent.

[Brief explanation of the drawing]

The first is a plan sectional view of a refrigerator equipped with means for implementing the present invention. FIG. 2 is an elevational sectional view of the refrigerator shown in FIG. 1. 1...refrigerator, 2...monkey cloth, 3...space, 4A, 4B
...Nitrogen supply closing port, 5...Duct, 6.
・・・． ...Fan, 7...Nitrogen layer. Figure 1 Figure 2

Claims (1)

[Claims] 1. Ventilated porous walls such as filter cloth are arranged at intervals along the inner wall surface of the refrigerator, and the space regulated by the intervals maintains a pressure slightly higher than the pressure inside the refrigerator across the porous walls. A method for replacing the atmosphere in a refrigerator, characterized by introducing gas into the space so as to develop a layer of gas flowing into the refrigerator through the porous wall, and at the same time exhausting the air in the refrigerator from around the center of the refrigerator. .