JPS6316029B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to an improvement in a method for extracting a freezing temperature sensor.

Conventionally, food items are rapidly frozen to below zero temperature and stored in a refrigerator to maintain their freshness. Since the time depends on various factors such as the air temperature in the freezing chamber, wind speed, air volume, type, size, and quality of the items to be frozen, a sensor is required to detect this. In this case, the sensor cannot detect the completion of freezing just by detecting the temperature in the freezing room, so it is necessary to determine the time when freezing is completed for each item to be frozen and control based on that elapsed time. is being carried out. As mentioned above, this method involves many factors related to the freezing time, making it troublesome and difficult to control with high precision. On the other hand, another method is to insert a temperature sensor into the product to be frozen and use this output to control the freezing device.It is also used to set the freezing time mentioned above, and is highly accurate. It is also possible to measure However, at the same time as freezing, the temperature sensor mentioned above was also frozen inside the frozen product.
In order to extract this, the frozen product must be thawed again, which may impede the use of the frozen product.
This requires a great deal of time and effort, and on the other hand, it cannot be easily taken out and used immediately, causing problems in the next freezing process.

The present invention has been made in view of the above points, and the temperature sensor is energized to heat the protection tube to thaw the frozen product surrounding the protection tube, thereby making it easier to remove the sensor from the frozen product. Because it has a removable structure, there is no trace left after the sensor is removed, and it can be handled like any other frozen product.

Next, this structure and embodiments will be described.

This temperature sensor can be roughly divided into thermocouple type and resistance type.

The former is due to thermoelectromotive force generated at the joint between dissimilar metals, and this is shown in FIGS. 1a and 1b. In figure a, the protection tube is a bare wire, and its tip is the junction point, and in figure b, a pair of thermocouples made of bare wire are inserted into the protection tube, and a thermocouple temperature sensor is used as a self-heating type. As an example of the wire in case a, if the wire is a copper-constantan thermocouple, the protection tube 1 is made of a wire with high electrical resistance, that is, constantan, and 2 is the protection tube 1.
It becomes a copper wire as a dissimilar metal wire. Therefore, heating of the protection tube 1 by energization is carried out by the protection tube itself. In case b, 2 and 3 are thermocouple wires, 2 is copper, and 3 is constantan, and since the protective tube 1 is indirectly heated by the internal wire, that is, constantan, when heated, the material There are no limitations.

In contrast to the structure in b, c is a structure in which wires 2 and 3 are further surrounded, a heating wire 5 is provided, and the structure is housed in the protective tube 1.

d is a resistance type temperature sensor that detects temperature by a change in resistance of metal due to temperature, and for example, a fine wire of platinum or copper is used as the resistance element wire 6. Furthermore, a heating wire 5 is also provided and housed within the protective tube 1.

When heating the sensor section, the temperature detection circuit switches the metal wires to a heating power source, energizes these metal wires, and heats the sensor by the resistance loss generated by the resistance of the wires themselves. c, d
This is an indirect heating type, in which the temperature detection circuit is disconnected during heating, and the heating wire 5 is energized to heat it.

FIG. 2 shows an example of its use, in which an indirectly heated thermionic temperature sensor is used. In the figure, 7 is a temperature controller, 8 is a cooling device, 9 is a freezing chamber, 10 is an item to be frozen, 11 is a switching switch, and 12 is a heating power source. This freezing sensor c shall be inserted into a representative frozen item among the items to be frozen.

If the switching switch 11 is now placed on the temperature measurement side on the right as shown in the figure, the cooling device 8 will be operated by the output of the temperature controller 7, and the freezing chamber 9 will be cooled at a predetermined temperature. will be held. The interior of the frozen product 10 is gradually cooled from the surface, and after a certain period of time, if the temperature sensor 1 inserted into the frozen product detects that the predetermined freezing temperature has been reached, the entire frozen product is cooled. This means that the product has completely frozen.

Next, when the switching switch 11 is turned on from the left temperature measurement side to the left and right heating sides, heating of the temperature sensor 1 is started. At this heating temperature, the protection tube 1 of the temperature sensor
As the area around the tube thaws, it is removed and inserted into the next frozen state, and the switching switch 1 is placed on the temperature measurement side again to start freezing, thereby performing freezing operation.

In this case, even if there are unfrozen parts inside the frozen product before the frozen product reaches the complete freezing temperature, if freezing is stopped in anticipation of the frozen product reaching the freezing temperature, the freezing time will be This makes it possible to save energy in the cooling device.

In the temperature sensors a and b shown in FIG. 1, since the metal wire itself is used as the heating wire, the outer diameter of the protective tube, which is limited by the heating power, can be made thinner and the structure becomes simpler.

In cases c and d, the heating power can be arbitrarily selected because the heating wire 5 is installed, but each has advantages and disadvantages, such as the diameter of the sensor becomes larger.
They are used differently depending on their purpose.

As described above, the present invention performs freezing with a temperature detection sensor directly inserted inside the item to be frozen.
After freezing is completed, the temperature sensor is energized and heated so that only the surrounding area surrounding the protection tube can be thawed and removed, making it possible to immediately respond to the next freezing, and to control the quality of frozen products.
Freezing time is shortened and energy-saving operation is possible.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of this freezing temperature sensor, a,
b is a self-heating thermoelectric temperature sensor, c is an indirect heating type thermionic temperature sensor, d is an indirect heating resistance temperature sensor, 1...Protective tube, and in Figure 1 a, a metal wire that also serves as a protective tube. , 2... Dissimilar metal strand, 3... Metal strand corresponding to dissimilar metal strand 2, 4... Junction point of strand, 5
... Heating wire, 6 ... Temperature-measuring resistance wire, Figure 2 is an example of the use of this temperature sensor, 7 ... Temperature controller,
8... Cooling device, 9... Freezing chamber, 10... Items to be frozen, 11... Switching switch, 12... Heating power source.

Claims (1)

[Claims] 1. In a temperature sensor that is inserted into the inside of the product to be frozen to detect the internal temperature and control the freezing device, after freezing is completed, the sensor is energized to heat the protection tube and the area surrounding the protection tube is heated. A method for extracting a temperature sensor for freezing, which is characterized by thawing a frozen product.