JPS632588B2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field
This invention relates to a vacuum CF storage device for storing CF.

Conventional technology CF storage is an abbreviation for Control Freezing-point.
Also called ice storage, it is a new storage method developed in recent years. The principle of this storage method is to lower the temperature of stored items such as vegetables, fruits, fish and livestock meat to just below their freezing point, and in some cases, to form a thin layer of ice on the surface of the stored items. It maintains the freshness of stored food without causing cell destruction. Compared to conventional refrigerated storage (0° to 5°C), CF storage: (1) maintains freshness extremely well; (2) extends shelf life; and (3) requires less time and effort to thaw, unlike freezing. There is no deterioration in quality caused by flaking or thawing; (4) The advantage is that the growth of mold and microorganisms is suppressed to the same extent as when frozen at -20℃.

And when performing temperature control in CF storage,
Usually, a method of circulating cold air in the atmosphere is used. However, this method has the disadvantage that precise temperature control is difficult because the temperature must be maintained just above the freezing point, and the response speed is slow when a sudden temperature change occurs.

Problems to be Solved by the Invention The present invention aims to solve the difficulty of temperature control in CF storage by using a vacuum.

Means for Solving the Problems Accordingly, in order to achieve the above objects, the present invention provides a vacuum-resistant container for storing stored items, and a cooling device for lowering the stored items in this container to a temperature close to the freezing point. , a pressure control device that controls the reduced pressure state in the container, and a temperature sensor device that detects the temperature of the stored material in the container based on a change in physical properties when water in the container undergoes a phase change to ice. A vacuum CF storage device characterized in that the pressure control device is controlled by the output of the temperature sensor device, and the temperature of the stored material in the container is controlled by adjusting the pressure thereby. I will provide a.

Function In the vacuum CF storage device according to the present invention, when the inside of the container is evacuated, the stored material is cooled to a predetermined temperature by the heat of vaporization removed from the surface. Temperature control can be performed relatively easily, precisely, and quickly by adjusting the way the heat of vaporization is removed, that is, the pressure.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.

The drawing shows an example of the apparatus according to the present invention, in which 1 is a vacuum container equipped with a heat insulating wall, in which a shelf 2 for placing items to be stored is provided. Further, a spray device 3 for spraying cooling water and a sensor device 4 for detecting internal temperature are arranged inside the vacuum container 1, and the sensor device 4 is combined with a water tank 5. The vacuum vessel 1 is connected to a vacuum pump 7 via a conduit 6, in which a pressure regulating valve 8 and a heat exchanger 9 are inserted as shown. The spray device 3 is connected to a cooling water supply source (not shown) through a heat exchanger 9, and the sensor device 4 is connected to a pressure regulating valve 8 to control its operation.

In the operation of the device configured as described above, first the spray device 3 is activated to spray ice as a pretreatment.
Glazing (forming a thin film of ice on the surface layer of the stored item). However, depending on the stored material, pretreatment may not be performed as it may have an adverse effect on the quality. Initial cooling from room temperature to a value close to a predetermined temperature is performed using vacuum cooling and spray equipment 3.
Although cooling is performed by cold water cooling or forced draft cooling, it is preferable to use vacuum cooling or a combination of vacuum cooling and cold water cooling.

After the pretreatment is completed in this manner, the pressure adjustment valve 8 is operated and controlled by the output signal from the sensor device 4 to perform pressure adjustment to reduce the pressure. In this case, as the sensor device 4 for temperature detection used for pressure regulation, a sensor that responds to a change in electrical resistance when water undergoes a phase change into ice is advantageously used, but other suitable detection means such as a thermocouple may also be used. You can also use

The pressure regulating valve 8 is preferably of the continuously adjustable type, but may also be of the simple on-off controlled type.

In addition, if the pressure inside the container 1 becomes very low and there is a risk that the stored material may dry out or wilt, the spray device 3 may periodically spray cold water. The present invention can also be applied to dry products stored at ice temperature, in which case spraying can be stopped and the pressure control method changed, and the process can be performed in a vacuum, which is expected to improve efficiency. It also reduces deterioration due to oxidation.

Effects As explained above, according to the present invention, the following effects can be obtained.

(1) Temperature control can be performed quickly, accurately, and easily by adjusting pressure.

(2) Because it instantly removes a large amount of heat, the heat of vaporization, it responds quickly and can quickly correct temperature changes.

(3) Since it is operated in a vacuum container, it is possible to perform sterile operation by filtering out incoming germs, except for germs attached to the stored items.

(4) This device can be easily applied to existing vacuum cooling equipment.

[Brief explanation of the drawing]

The drawings are schematic diagrams showing one embodiment of the present invention. In the figure, 1: vacuum container, 2: shelf, 3: spray device, 4: sensor device, 6: conduit, 7: vacuum pump, 8: pressure adjustment valve, 9: heat exchanger.

Claims (1)

[Claims] 1. A vacuum-resistant container that stores stored items, a cooling device that lowers the stored items in this container to a temperature close to the freezing point, a pressure control device that controls the reduced pressure state in the container, and a vacuum-resistant container that stores the stored items. and a temperature sensor device that detects the temperature of the stored material in the container based on a change in physical properties when the phase changes to ice, and the pressure control device is controlled by the output of the temperature sensor device. A vacuum CF storage device characterized in that the temperature of the stored material in the container is controlled by adjusting the pressure.