JP4121760B2 - Method and apparatus for freezing water triple-point cell - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for icing a triple point cell of water for realizing a triple point temperature of water necessary for determining a temperature scale such as a thermometer.
[0002]
[Prior art]
The triple point temperature of water is a temperature at which a solid, liquid and gas of water coexist, and is realized at a vapor pressure of 611 Pa. The temperature is defined as 273.16K (0.01 ° C) in the 1990 International Temperature Scale (ITS-90), and generally high-purity water having the same isotopic composition as ocean water as shown in FIG. It is realized in a glass cell in which is encapsulated. And the triple point temperature of water is used when determining the temperature scale of a platinum resistance thermometer.
[0003]
A conventional water triple point cell 1 shown in FIG. 4 has a cell container 3 which is cylindrical and has a top and a bottom sealed. Water W is stored in the cell container 3. In the water W in the cell container 3, a bottomed cylindrical thermometer well 5 is inserted and disposed.
[0004]
In order to realize the triple point temperature of water using such a triple point cell 1 of water, first, the triple point cell of water is sufficiently pre-cooled using ice shave.
[0005]
Next, the thermometer well 5 is drained, a small amount of ethanol is added, and a small amount of dry ice powder is added.
[0006]
When dry ice runs out, add a small amount of dry ice. This operation is repeated until an appropriate amount of ice is attached to the bottom of the thermometer well 5.
[0007]
When the ice is attached, wipe off the ethanol in the thermometer well 5, and this time put dry ice powder to the surface of the water.
[0008]
As dry ice sublimates, it is always replenished so that dry ice comes to the surface. This operation is repeated until the ice I uniformly adheres to the entire thermometer well 5.
[0009]
In this way, ice I is attached to the outer periphery of the thermometer well 5 to realize a triple point T of water.
[0010]
In addition, as a coolant filled in the thermometer well 5, liquid nitrogen can also be used in addition to dry ice.
[0011]
[Problems to be solved by the invention]
However, the above method has a problem that it takes time to load the thermometer well 5 with dry ice powder, and it takes about 1 hour to freeze the ice.
[0012]
Further, since dry ice having a temperature as low as −80 ° C. compared to normal temperature is used, there is a problem that the ice on the outer periphery of the thermometer well is easily cracked and uniform ice attachment is difficult.
[0013]
Further, it is not always easy to ice the outer circumference of the thermometer well with a uniform thickness in the longitudinal direction, and there is a problem that skill is required.
[0014]
An object of the present invention is to solve the above-mentioned problems, and is a triple-point water cell that can be easily charged with a coolant, can be iced in a short time, and can be uniformly iced without causing cracks. An object of the present invention is to provide a method for freezing ice and a freezing device for a triple-point cell of water.
[0015]
[Means for Solving the Problems]
The first feature of the present invention is:
In a state where the thermometer well is immersed in the water stored in the cell container, ice is applied to the outer periphery of the thermometer well by supplying a coolant into the thermometer well, and water is applied to the water surface in the cell container. In the method of icing a triple point cell of water to form a solid, liquid, gas triple point,
The coolant, Ri refrigerant der cooled in the refrigerator,
The refrigerant is supplied to the thermometer well and sucked from the thermometer well,
Supply of the refrigerant to the thermometer well is performed by a refrigerant supply pipe inserted into the thermometer well,
The suction of the refrigerant from the thermometer well is performed by a refrigerant suction pipe inserted into the thermometer well ,
By positioning the opening of the refrigerant supply pipe and the opening of the refrigerant suction pipe at the bottom of the thermometer well, supplying the refrigerant from the refrigerant supply pipe and sucking the refrigerant into the refrigerant suction pipe, Cooling the thermometer well to form an ice mass on the outer periphery of the bottom of the thermometer well,
Raising the opening of the refrigerant suction tube from the bottom of the thermometer well to the level of the water surface in the cell container in the thermometer well;
An opening of the refrigerant supply pipe is raised from the bottom of the thermometer well to the position of the water surface in the cell container in the thermometer well, and from the ice block formed at the bottom of the thermometer well, the cell container The purpose is to apply ice with the same thickness as the ice block to the outer periphery of the thermometer well to the position of the water surface inside.
[0016]
The second feature of the present invention is that
An apparatus for carrying out the method of icing a triple-point water cell, which is the first feature of the present invention,
A cell container storing water;
A thermometer well arranged in a state immersed in water in the cell container;
A refrigerator that cools the refrigerant;
A circulation pump for supplying and recovering the refrigerant cooled by the refrigerator to the thermometer well;
A refrigerant supply pipe connected to the discharge port of the circulation pump and having an opening at the tip thereof inserted into the thermometer well, and supplying a cooled refrigerant into the thermometer well;
A refrigerant suction pipe the opening of the tip is connected to the suction port of the circulating pump is inserted into the thermometer in the well, it sucks the refrigerant of the thermometer in the well,
With
The refrigerant supply pipe and the refrigerant suction pipe are:
After each opening is positioned at the bottom of the thermometer well, the thermometer well is cooled by supplying the refrigerant from the refrigerant supply pipe and sucking the refrigerant through the refrigerant suction pipe. An ice block is formed on the outer circumference of the bottom of the total well,
Raising the opening of the refrigerant suction tube from the bottom of the thermometer well to the level of the water surface in the cell container in the thermometer well;
By moving the opening of the refrigerant supply pipe from the bottom of the thermometer well to the position of the water surface in the cell container in the thermometer well, the cell is removed from the ice block formed at the bottom of the thermometer well. To the position of the water surface in the container, so that the ice of the same thickness as the ice block can be applied to the outer periphery of the thermometer well,
In that it has been disposed to be movable in the vertical direction in the thermometer in the well.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to FIGS.
[0018]
In FIG. 1, the code | symbol 11 shows the freezing apparatus of the triple point cell of water which is one embodiment of this invention. The water triple point cell freezing device 11 includes a water triple point cell 12, and the water triple point cell 12 includes a cell container 13 and a thermometer well 15. The cell container 13 is for storing water for freezing inside thereof, and has a bottomed cylindrical shape with a sealed upper end. Inside the cell container 13, a bottomed tubular thermometer well 15 is provided. The thermometer well 15 is for supplying a refrigerant to the inside thereof and icing the outer periphery thereof. The thermometer well 15 is arranged in the vertical direction along the axis of the cell container 13, and the upper end of the thermometer well 15 is a cell. The upper end of the container 13 is provided so as to protrude outside.
[0019]
Inserted into the thermometer well 15 are a distal end portion 17 a of a refrigerant supply pipe 17 that supplies the refrigerant to the thermometer well 15 and a distal end portion 19 a of a refrigerant suction pipe 19 that sucks the refrigerant from the thermometer well 15. . The refrigerant supply pipe 17 and the refrigerant suction pipe 19 are inserted from the upper opening 21 of the thermometer well 15, and are individually arranged to be movable in the vertical direction.
[0020]
The refrigerant supply pipe 17 and the refrigerant suction pipe 19 are made of a flexible tube made of ethylene tetrafluoride. A circulation pump 23 is provided at the other end of the refrigerant supply pipe 17 and the refrigerant suction pipe 19, and the circulation pump 23 is attached to the refrigerator 25. The refrigerant cooled by the refrigerator 25 is supplied to the thermometer well 15 through the refrigerant supply pipe 17 by the circulation pump 23. The refrigerant supplied to the thermometer well 15 is collected by the circulation pump 23 through the refrigerant suction pipe 19 and cooled again by the refrigerator 25. Note that ethanol is used as the refrigerant.
[0021]
The refrigerator 25 is provided with a monitor thermometer 27 so that the temperature of the refrigerant in the refrigerator 25 can be measured.
[0022]
The refrigerant supply pipe 17 is provided with a bypass pipe 31 via a valve 29. The bypass pipe 31 can return the refrigerant to the refrigerator 25 through the pipe. By adjusting the valve 29, a part of the refrigerant discharged from the circulation pump 23 is transferred to the refrigerator 25. Returning, the amount of the refrigerant supplied to the thermometer well 15 can be adjusted.
[0023]
In the icing device 11 of the triple-point cell of water having such a configuration, when the refrigerator 25 is set to −50 ° C. and the circulation pump 23 is operated, the cooled ethanol is discharged from the discharge port of the circulation pump 23. The ethanol is supplied to the thermometer well 15 through the refrigerant supply pipe 17. Usually, the temperature of ethanol in the thermometer well 15 is -20 ° C to -60 ° C. This ethanol cools the water in the cell container 13 through the tube wall of the thermometer well 15, and ice is applied to the outer periphery of the thermometer well 15. Thereafter, the ethanol is sucked into the circulation pump 23 through the refrigerant suction pipe 19 and is sucked into the suction port of the circulation pump 23 and collected. In this manner, the cooled ethanol is circulated through the thermometer well 15 so that the outer periphery thereof is iced.
[0024]
As described above, in the ice attaching device 11 for the triple-point cell of water, the cooled ethanol circulates in the thermometer well 15, so that the case where powder such as dry ice is used is used. In comparison, the contact with the inner wall of the thermometer well 15 can be kept good. Therefore, heat conduction through the tube wall can be performed efficiently, and icing can be performed in a short time. Moreover, since the temperature of ethanol can be appropriately set using the refrigerator 25 and the temperature of ethanol supplied to the thermometer well 15 can be set from -20 ° C to -60 ° C, extremely low temperature dry ice or liquid Compared with the case of using nitrogen, it can be cooled at a temperature relatively close to room temperature, and therefore, it is possible to prevent the ice from cracking.
[0025]
Next, with reference to FIGS. 2 (a) to 2 (d), a method of actually icing using the water icing device 11 for the triple-point cell of water will be described.
[0026]
First, a refrigerant supply pipe 17 and a refrigerant suction pipe 19 made of ethylene tetrafluoride are inserted into the thermometer well 15 of the triple-point cell 12 of sufficiently pre-cooled water, and the openings 17b of the respective leading end portions 17a and 19a, 19b is inserted to the bottom. Then, ethanol is circulated, and an appropriate amount of ice 1 is applied to the bottom 15a of the thermometer well 15 as shown in FIG.
[0027]
Next, as shown in FIG. 2B, the opening 19 b of the refrigerant suction pipe 19 is connected to the water surface S in the cell container 13 while the opening 17 b of the refrigerant supply pipe 17 is fixed to the bottom 15 a of the thermometer well 15. Position it close. Then, the cooled ethanol is supplied into the thermometer well 15 from the opening 17 b of the refrigerant supply pipe 17, rises in the thermometer well 15, and is sucked from the opening 19 b of the refrigerant suction pipe 19. In the course of rising in the thermometer well 15, ethanol freezes the outer periphery of the thermometer well 15 while the temperature rises gradually. Therefore, as shown in FIG. 2 (b), the outer periphery of the thermometer well 15 is iced so that it gradually becomes thinner from the bottom 15a toward the water surface S.
[0028]
Next, as shown in FIG. 2C, the opening 17b of the refrigerant supply pipe 17 is gradually moved upward while observing the degree of ice in order to make the ice uniform. By doing in this way, ice is further applied on the already formed ice by the relatively low-temperature refrigerant discharged from the opening 17b of the refrigerant supply pipe 17 and whose temperature has not yet risen. Since ice tends to stick to a portion slightly ahead of the opening 17b of the refrigerant supply pipe 17, if ice is applied while adjusting the position of the opening 17b of the tip 17a, ice can be attached relatively easily. it can. However, since the water surface freezes as the opening 17b of the tip 17a is moved upward, it must be solved each time.
[0029]
In this way, as shown in FIG. 2 (d), the ice I having a uniform thickness from the bottom 15 a to the water surface S can be applied to the outer periphery of the thermometer well 15. In practice, a practical amount of ice can be applied in a relatively short time of approximately 10 minutes. A triple point T of water is formed between the water W, the ice I, and the water vapor V.
[0030]
As described above, in the ice attaching method using the ice attaching device 11 of the triple-point cell for water, since the cooled ethanol is circulated in the thermometer well 15, dry ice or the like is used. Compared with the case of using the powder of this, the contact with the inner wall of the thermometer well 15 is good, so that heat conduction through the tube wall can be efficiently performed, and the time required for icing can be shortened. . Moreover, since the temperature of ethanol can be appropriately set by the refrigerator 25, it can be cooled at a temperature relatively close to room temperature as compared with the case of using extremely low temperature dry ice or liquid nitrogen, and thus cracks occur in the ice. Can be prevented.
[0031]
Furthermore, in this method, since the opening 17b of the refrigerant supply pipe 17 and the opening 19b of the refrigerant suction pipe 19 can be moved in the vertical direction, the thickness of the ice around the thermometer well 15 is reduced. These openings 17b and 19b can be adjusted by appropriately moving them. Therefore, ice with a uniform thickness in the vertical direction can be easily performed. Furthermore, since ice can be attached to an arbitrary place by changing the position of the tip of the supply pipe, the flexibility of the ice attaching operation can be improved.
[0032]
As a precaution for this work, as described above, the water surface may freeze in a short time if the opening 17b of the tip 17a is moved upward. In such a case, it is necessary to solve this. There is. This is because if left as it is, it cannot be said that there is no possibility that the cell is damaged by the pressure applied in the cell. However, as described above, since ice is applied at a relatively high temperature, the ice is not easily cracked, and there are fewer work procedures than conventional methods of applying ice with dry ice powder. There is an effect that the burden is reduced.
[0033]
FIG. 3 shows the triple point temperature when iced with this system using the same cell and the triple point temperature when iced with conventional dry ice with respect to the triple point temperature of a standard triple point cell. Each is compared by difference. The figure shows the temperature difference from the standard triple point cell for 4 days immediately after icing.
[0034]
Usually, it is said that immediately after applying ice, it shows a temperature lower than the triple point temperature and becomes stable with time.
[0035]
Even in this result, the temperature seems to be low immediately after the ice is attached, but it is almost the same temperature as time passes. In addition, similar results are obtained in the experimental data other than those listed here, although there is a slight difference. Furthermore, when it sees in FIG. 3, although it seems that there exists a temperature difference by the difference in how to attach ice, this difference of this grade is a range which can be disregarded actually and is satisfactory.
[0036]
In the above-described embodiment, the refrigerant supply pipe 17 and the refrigerant suction pipe 19 are made of tetrafluoroethylene. However, the present invention is not limited to this, and other materials may be used as long as they have flexibility at low temperatures. .
[0037]
【The invention's effect】
As described above, in the method of icing a water triple point cell of the present invention, the coolant is supplied into the thermometer well while the thermometer well is immersed in the water stored in the cell container. In this method of icing a triple-point water cell in which the outer circumference of the thermometer well is iced to form a triple point of water solid, liquid and gas on the water surface in the cell container, In the iced apparatus for water triple point cell according to the present invention, a cooled water refrigerant, a cell container storing water, a thermometer well immersed in the water in the cell container, a refrigerant A refrigerant that is connected to the refrigerator and circulates the refrigerant, and one end of which is inserted into the thermometer well and the other end is connected to the circulation pump and is cooled by the refrigerator A refrigerant supply pipe for supplying the liquid into the thermometer well And a circulation pump connected to the other end of the thermometer well, and a refrigerant suction pipe for sucking the refrigerant in the thermometer well and returning it to the refrigerator. By circulating through the measuring well and cooling the thermometer well, the outer periphery of the thermometer well is iced, so it is easy to fill the coolant, can be iced in a short time, and Uniform ice can be applied without causing cracks.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic configuration diagram showing a water triple point cell icing apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram showing a method of icing using the water triple point cell icing device shown in FIG. 1, wherein (a) is a diagram showing a state in which icing is performed on the bottom of a thermometer well; (B) is a figure which shows the state which raised the refrigerant | coolant suction pipe | tube and performed ice attachment, (c) is a figure which shows the icing state when a refrigerant | coolant supply pipe | tube is raised to the intermediate part of a thermometer well. (D) is a figure which shows the icing state when raising a refrigerant | coolant supply pipe | tube to a water surface position.
FIG. 3 is a diagram comparing the triple point temperature when icing is performed using the water triple point cell icing apparatus of the present invention and when the conventional triple point cell is iced.
FIG. 4 is a schematic longitudinal sectional view showing a conventional triple point cell for water.
[Explanation of symbols]
11 Water triple point cell freezing device 12 Water triple point cell 13 Cell container 15 Thermometer well 15a Bottom part 17 Refrigerant supply pipe 17a Tip part 17b Opening part 19 Refrigerant suction pipe 19a Tip part 19b Opening part 23 Circulation pump 25 Refrigeration Machine

Claims (2)

In a state where the thermometer well is immersed in the water stored in the cell container, ice is applied to the outer periphery of the thermometer well by supplying a coolant into the thermometer well, and water is applied to the water surface in the cell container. In the method of icing a triple point cell of water to form a solid, liquid, gas triple point,
The coolant, Ri refrigerant der cooled in the refrigerator,
The refrigerant is supplied to the thermometer well and sucked from the thermometer well,
Supply of the refrigerant to the thermometer well is performed by a refrigerant supply pipe inserted into the thermometer well,
The suction of the refrigerant from the thermometer well is performed by a refrigerant suction pipe inserted into the thermometer well ,
By positioning the opening of the refrigerant supply pipe and the opening of the refrigerant suction pipe at the bottom of the thermometer well, supplying the refrigerant from the refrigerant supply pipe and sucking the refrigerant into the refrigerant suction pipe, Cooling the thermometer well to form an ice mass on the outer periphery of the bottom of the thermometer well,
Raising the opening of the refrigerant suction tube from the bottom of the thermometer well to the level of the water surface in the cell container in the thermometer well;
From the bottom of the thermometer well to the position of the water surface in the cell container in the thermometer well, the opening of the refrigerant supply pipe is raised to the cell container from the ice block formed at the bottom of the thermometer well until the water surface position in the the outer periphery of the thermometer well, ice with a method of the triple point cell water you and performing ice with the same thickness as the ice blocks. An apparatus for carrying out the method of icing a triple-point cell of water according to claim 1,
A cell container storing water;
A thermometer well arranged in a state immersed in water in the cell container;
A refrigerator that cools the refrigerant;
A circulation pump for supplying and recovering the refrigerant cooled by the refrigerator to the thermometer well;
A refrigerant supply pipe connected to the discharge port of the circulation pump and having an opening at the tip thereof inserted into the thermometer well, and supplying a cooled refrigerant into the thermometer well;
A refrigerant suction pipe the opening of the tip is connected to the suction port of the circulating pump is inserted into the thermometer in the well, it sucks the refrigerant of the thermometer in the well,
With
The refrigerant supply pipe and the refrigerant suction pipe are:
After each opening is positioned at the bottom of the thermometer well, the thermometer well is cooled by supplying the refrigerant from the refrigerant supply pipe and sucking the refrigerant through the refrigerant suction pipe. An ice block is formed on the outer circumference of the bottom of the total well,
Raising the opening of the refrigerant suction tube from the bottom of the thermometer well to the level of the water surface in the cell container in the thermometer well;
By moving the opening of the refrigerant supply pipe from the bottom of the thermometer well to the position of the water surface in the cell container in the thermometer well, the cell is removed from the ice block formed at the bottom of the thermometer well. To the position of the water surface in the container, so that the ice of the same thickness as the ice block can be applied to the outer periphery of the thermometer well,
An apparatus for icing a triple-point cell of water , wherein the apparatus is movably arranged in the vertical direction in the thermometer well .

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