JP2007139757A - Thermal insulation container for thermometry - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact thermal insulation container for thermometry capable of prolonged use in a limited space, while having excellent thermal insulation performance. <P>SOLUTION: The thermal insulation container for the thermometry 1 comprises a logger storage container 2 capable of storing a logger 5 recording temperature data, a heat regenerator inner layer 3 filled with iced water 11 which is located outside of the logger storage container 2, an inner vessel 12 which is arranged outside of the heat regenerator inner layer 3, and is filled with the iced water 11, and a thermal insulation outer layer 4 including a low thermal conductivity material 13 which is arranged outside of the inner vessel 12. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an insulated container for temperature measurement. More specifically, the present invention relates to a heat-insulating container for temperature measurement that is compact while having excellent heat insulation performance and can be used for a long time in a limited space.

  As a device for measuring the temperature data of the object to be heat-treated in the continuous furnace and the temperature data inside the continuous furnace, there is a temperature measuring device that is used by moving the inside of the continuous furnace together with the object to be processed. For example, as shown in FIG. 2, such a temperature measuring device includes a thermocouple that measures an external (in-furnace) temperature in a temperature measurement heat insulating container 10 including an inner layer 23, an outer layer 24, and a lid 15. The logger 5 to which the temperature sensor 6 is connected is housed. In addition, although the material which comprises the inner layer 23 and the outer layer 24 is suitably selected by the temperature environment etc. to which it is exposed, a thermal diffusivity is small and bricks, ceramic fiber, etc. with high heat insulation are employ | adopted.

  This type of temperature measurement insulated container has been conventionally used in continuous furnaces in various fields. For example, in a relatively low temperature continuous furnace of about 300 ° C. or lower, a vacuum heat insulating container or the like having a double wall structure is used (for example, see Patent Document 1). Further, there is an example in which ice water is used as a material having a large heat capacity (see, for example, Patent Document 2). In the case of using ice water, heat of fusion and latent heat of vaporization can be used, so that it can be effectively insulated. Furthermore, a heat-insulating container for temperature measurement having a configuration in which a data recorder (logger) is housed in a vacuum bottle together with ice and the vacuum bottle is surrounded by a heat insulating material is disclosed (for example, see Patent Document 3).

The heat resistant temperature of a logger that is generally used is about 50 to 90 ° C. For this reason, when using this logger for a long time under high temperature conditions, it is necessary to use the heat insulation container which has higher heat insulation performance. However, when trying to give the conventional heat insulating container high heat insulating performance, the size tends to increase. Therefore, when there is a restriction on the passage cross-sectional area in the continuous furnace, there has been a problem that a heat insulating container having a large size in order to exhibit excellent heat insulating performance cannot be used.
Japanese Utility Model Publication No. 64-51815 Japanese Utility Model Publication No. 61-145300 JP 9-280968 A

  The present invention has been made in view of such problems of the prior art, and the object of the present invention is to be compact while having excellent heat insulation performance, and in a limited space for a long time. The object is to provide a heat insulating container for temperature measurement that can be used.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have sequentially arranged a heat storage inner layer filled with ice water and a heat insulating outer layer containing a low thermal conductivity material on the outside of the logger storage container for storing the logger. The present inventors have found that the above-described problems can be achieved and have completed the present invention.

  That is, according to the present invention, the following thermal insulation container for temperature measurement is provided.

  [1] A logger storage container capable of storing a logger for recording temperature data, a heat storage inner layer disposed outside the logger storage container and filled with ice water, and disposed outside the heat storage inner layer and filled with the ice water And a heat insulating outer layer including a low thermal conductivity material disposed outside the inner container.

[2] The logger storage container is disposed substantially at the center, and the thickness (d ₁ ) of the heat storage inner layer with respect to the sum of the thickness (d ₁ ) of the heat storage inner layer and the thickness (d ₂ ) of the heat insulation outer layer. The heat insulation container for temperature measurement according to [1], wherein the ratio value (d ₁ / (d ₁ + d ₂ )) is in the range of 0.6 to 0.7.

  [3] The temperature measurement heat insulation container according to [1] or [2], wherein the inner container is a vacuum heat insulation container.

  [4] Any of the above [1] to [3], wherein the low thermal conductivity material is at least one selected from the group consisting of ceramic fiber, glass wool, rock wool, calcium silicate heat insulating material, and fine porous structure heat insulating material. A heat-insulating container for temperature measurement according to crab.

  The heat-insulating container for temperature measurement of the present invention is compact while having excellent heat insulation performance, and has an effect that it can be used for a long time in a limited space.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below, but the present invention is not limited to the following embodiment, and is based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention. It should be understood that modifications and improvements as appropriate to the following embodiments also fall within the scope of the present invention.

  FIG. 1 is a cross-sectional view schematically showing one embodiment of a temperature measurement heat insulating container of the present invention. As shown in FIG. 1, the temperature measurement heat insulation container 1 of this embodiment includes a logger storage container 2, a heat storage inner layer 3, and a heat insulation outer layer 4. When actually using the heat insulation container 1 for temperature measurement, the logger 5 for recording data of the external temperature is stored in the heat insulating space 8 in the logger storage container 2. The logger 5 is connected to a temperature sensor 6 capable of measuring the external temperature of the temperature measurement heat insulating container 1.

  The heat storage inner layer 3 disposed outside the logger storage container 2 is filled with ice water 11. Moreover, the heat insulation outer layer 4 arrange | positioned on the outer side of this heat storage inner layer 3 is comprised by the low thermal conductivity material 13 arrange | positioned on the outer side of this inner container 12 which can be filled with the ice water 11, and this inner container 12. FIG. In FIG. 1, reference numeral 14 denotes a support base on which the logger storage container 2 is placed, and reference numeral 15 denotes a lid.

  A layer made of a material having a large heat capacity, that is, a heat storage inner layer 3 is provided in a portion close to the logger 5 that is protected from external heat. The thickness of the heat storage inner layer 3 is, for example, 20 to 100 mm. In addition, there is no restriction | limiting in particular about the thermal conductivity of the material which comprises the thermal storage inner layer 3. FIG. A material having a large heat capacity constituting the heat storage inner layer 3 is ice water 11. By using ice water 11, heat of fusion can also be used. The ice produced using a normal ice container can be used. By putting the logger storage container 2 and ice in the inner container 12 and filling the ice gap with water, for example, the heat storage inner layer 3 having an ice content of 50 to 60 vol% can be configured. By using the ice water 11 having a high ice content, a higher heat insulation effect is exhibited. If ice is produced so as to match the space shape between the inner container 12 and the logger storage container 2, the heat storage inner layer 3 having an ice content of 80 to 90% by volume can be formed.

  In addition, the heat-resistant temperature of a normal logger is less than 100 ° C. However, when a logger having a heat resistant temperature of 100 ° C. or higher is used, it is also possible to exert a further excellent heat insulating effect by utilizing the latent heat of vaporization of water. However, the evaporated water may disturb the atmosphere in the continuous furnace. Therefore, it is necessary to consider the influence on the object to be heated arranged in the continuous furnace.

  A layer made of a low thermal conductivity material, that is, a heat insulating outer layer 4 is provided on the outer portion of the heat storage inner layer 3. The thickness of this heat insulation outer layer 4 is 20-100 mm, for example. In addition, there is no restriction | limiting in particular about the heat capacity of the heat insulation outer layer 4. FIG. As the low thermal conductivity material constituting the heat insulation outer layer 4, a fibrous inorganic material having a high porosity is preferably used. More specifically, a ceramic fiber, glass wool, rock wool, calcium silicate heat insulating material, or a fine porous structure heat insulating material that is generally used as a lightweight heat insulating material, or a mixed laminate obtained by combining a plurality of these is preferably used. .

  The above-mentioned fine porous structure heat insulating material refers to a heat insulating material containing a component such as silica, titania, alumina, etc. and having a fine porous structure formed therein. More specifically, a commercially available product such as a trade name “Microtherm” (manufactured by Nippon Microtherm Co., Ltd.) can be mentioned as a suitable example.

  The thermal conductivity of the heat insulating outer layer 4 is temperature-dependent, and is, for example, about 0.03 to 0.08 kcal / (m · h · ° C.) when used in a continuous furnace in a temperature range around 500 ° C. .

  It is preferable to use a vacuum heat insulating container as the inner container 12. When a vacuum heat insulating container is used for the inner container 12, the vacuum heat insulating wall constituting the vacuum heat insulating container functions as a part of the heat insulating outer layer 4. Therefore, the heat conductivity as the whole heat insulation outer layer 4 is further reduced, and the more excellent heat insulation effect is exhibited.

  The structure of the vacuum heat insulating wall is usually a double wall structure having a vacuum portion between the inner wall and the outer wall. For this reason, the theoretical thermal conductivity of the vacuum part is zero. However, since heat transfer by radiation and heat conduction from the portion connecting the inner wall and the outer wall occur, a certain amount of heat transfer can occur in the entire vacuum heat insulating wall. However, there is very little heat transfer under low temperature conditions of about 300 ° C. or lower. For example, when the thickness of the vacuum heat insulating wall is 7.5 mm, the apparent thermal conductivity of the vacuum heat insulating wall is about 0.005 kcal / (m · h · ° C.).

  Here, assuming that the thickness of the ceramic fiber is 80 mm and the thermal conductivity is about 0.06 kcal / (m · h · ° C.), a heat insulating outer layer comprising a vacuum heat insulating wall having a thickness of 7.5 mm and a ceramic fiber having a thickness of 80 mm. The overall thermal conductivity is about (87.5 / (7.5 / 0.005 + 80 / 0.06)) = 0.03 kcal / (m · h · ° C.). Therefore, for example, compared with the case where the heat insulating outer layer having a thickness of 80 mm is formed only of ceramic fibers, the heat transfer amount can be halved by applying a vacuum heat insulating wall of 7.5 mm to the 80 mm.

  Note that heat transfer due to radiation is more likely to occur in the vacuum heat insulating wall as the ambient temperature increases. That is, the apparent thermal conductivity of the vacuum heat insulating wall increases dramatically as the ambient temperature rises. For this reason, when the atmospheric temperature (outside temperature) of the vacuum heat insulating wall becomes 300 ° C. or higher, the heat insulating performance tends to be lowered. Therefore, it is preferable to place a vacuum heat insulating wall (vacuum heat insulating container) in the innermost part of the heat insulating outer layer 4 so that the vacuum heat insulating wall is not exposed to high temperature conditions because a more excellent heat insulating effect is exhibited.

The logger storage container 2 is disposed substantially at the center of the heat insulation container 1 for temperature measurement, and the heat storage inner layer with respect to the sum (d ₁ + d ₂ ) of the thickness d ₁ of the heat storage inner layer and the thickness d ₂ of the heat insulation outer layer. The value of the ratio of thickness d ₁ (d ₁ / (d ₁ + d ₂ )) is preferably in the range of 0.6 to 0.7, and more preferably in the range of 0.625 to 0.675. . By setting “d ₁ / (d ₁ + d ₂ )” to the above numerical range, excellent heat insulation performance is exhibited with limited dimensions. Therefore, the heat-insulating container 1 for temperature measurement of the present embodiment is compact while having excellent heat insulating performance, and can be used for a long time in a limited space.

  As described above, the temperature measurement heat insulation container 1 of the present embodiment is compact while having excellent heat insulation performance. Therefore, the heat insulation container 1 for temperature measurement of the present embodiment is suitable as a heat insulation container for constituting a temperature measurement device that is used by moving the inside of the continuous furnace together with the workpieces in various continuous furnaces.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples.

(Unsteady heat transfer calculation using a planar model (Reference Examples 1 to 5))
FIG. 3 is a cross-sectional view schematically showing a planar model for unsteady heat transfer calculation. The planar model 25 is a model composed of an inner layer 23 and an outer layer 24 each having a thickness of 0.1 m, and the internal temperature T ₁ and the external temperature T ₂ in the initial state are both 20 ° C. Table 1 shows combinations of materials of the inner layer and the outer layer. Table 2 shows physical property values of the materials shown in Table 1. In Table 2, the thermal conductivity λ of water is expressed as “1000 (kcal / m · h · ° C.)”, which is a numerical value considering water convection. From this initial state (T ₁ = T ₂ = 20 ° C.), the change in the internal temperature T ₁ when only the external temperature T ₂ was suddenly changed to 200 ° C. was calculated. The results are shown in FIG.

  As is clear from FIG. 4, even when the thermal diffusivity is the same, when a material having a different heat capacity and thermal conductivity is used, a material having a larger heat capacity is disposed in the inner layer, and a material having a lower thermal conductivity is used. Is preferably disposed in the outer layer (reference example 3 and reference example 4 are compared). Further, it is apparent that Reference Example 5 in which the inner layer is composed of water and the outer layer is composed of ceramic fibers exhibits the most excellent heat insulating effect.

(Unsteady heat transfer calculation using a cylindrical model)
FIG. 5 is a cross-sectional view schematically showing a cylindrical model for unsteady heat transfer calculation. The cylindrical model 35 has the same diameter and height. The heat-insulated space 38, the heat storage inner layer 3, and the heat insulating outer layer 4 (thermal conductivity = λ) are similar to each other. In FIG. 5, reference numeral 37 indicates the central axis, reference numeral D indicates the total layer thickness (the sum of the thickness d ₁ of the heat storage inner layer and the thickness d ₂ of the heat insulating outer layer), and the reference symbol R _i indicates the heat-insulated space radius. Indicates.

Temperature of all areas is constant _{(T 1 = T 2 = T} 0 (T 0: initial temperature)) from the initial state of, when obtained by a sudden change in the external temperature _{T 2} only _{T e} (° C.), the internal temperatures _{T 1} The change of was calculated. The results are shown in FIGS. When the time required for the temperature difference between the internal temperature T ₁ and the external temperature T ₂ to become 1 / e (e≈2.718) of (T _e −T ₀ ) is “representative arrival time H”. It can be evaluated that the longer the representative arrival time H is, the better the heat insulation performance is.

6 and 7 are graphs showing the results of unsteady heat transfer calculation using a cylindrical model. In FIG. 6, the thermal conductivity of the heat insulating outer layer 4 is constant (λ / R _i = 1.7), and the parameters of the total layer thickness are D / R _i = 4, D / R _i = 5, and D / R _i In the case of setting = 6, the representative temperature arrival time H (h) is plotted against the thickness of the heat storage inner layer / the total layer thickness (d ₁ / D). As is clear from FIG. 6, regardless of the value of the parameter (D / R _i ) of the total layer thickness, when the value of d ₁ / D is in the range of 0.6 to 0.7, It turns out that the outstanding heat insulation effect is exhibited.

In FIG. 7, when the parameters of the thermal conductivity of the heat insulating outer layer 4 are set to λ / R _i = 0.3, λ / R _i = 1.3, and λ / R _i = 3.3, the total layer thickness The optimum d ₁ / D (d _{1 opt./D} ) value is plotted against (D / R _i ). As is clear from FIG. 7, regardless of the value of the thermal conductivity parameter (λ / R _i ), the optimum value of d ₁ / D (d _{1 opt./D} ) is 0.6 to It can be seen that it is within the range of 0.7.

(Examples 1-4, Comparative Examples 1 and 2)
A temperature measurement insulated container 1 (Examples 1 to 4, Comparative Examples 1 and 2) having the configuration shown in FIG. 1 was produced. Table 3 shows the dimensions of the constituent members constituting the temperature measurement heat insulating container 1. Also shows the material and the thickness _{d 1} of the heat storage inner layer 3, the material and thickness _{d 2} of the heat insulating layer 4, and the value of _"d 1 _{/ (d} 1 + _{d 2)"} in Table 4. In addition, in order to measure the temperature in the logger storage container 2, a thermocouple was inserted into the logger storage container 2 instead of storing the logger. Moreover, the content rate of the ice water of the ice water used in order to produce the heat insulation container 1 for temperature measurement of Examples 1-4 was about 60 volume%.

  Each of the temperature-insulating heat insulation containers 1 thus prepared was placed in a batch type electric furnace, and as shown in FIG. 8, the temperature was increased by 5 hours → 500 ° C. × 3 hours hold → temperature decrease 2 hours. Table 4 shows the measurement results of the temperature reached in the logger storage container 2 for each of the temperature measurement heat insulation containers 1. FIG. 8 is a graph in which the temperature (° C.) in the logger storage container is plotted against the time (h) for the temperature measurement thermal insulation containers of each Example and Comparative Example.

As shown in Table 4, the heat insulation containers for temperature measurement of Examples 1 to 4 have a lower temperature reached in the logger storage container than the heat insulation containers for temperature measurement of Comparative Examples 1 and 2, and have an excellent heat insulation effect. It is clear that it is. Further, by setting the value of “d ₁ / (d ₁ + d ₂ )” within the range of 0.6 to 0.7, it is possible to further reduce the temperature reached in the logger storage container (Example 2). , 4). That is, it is clear that even if the dimensions of the temperature measurement heat insulation container are the same, a better heat insulation effect can be exhibited by setting the ratio of the thickness of the heat storage inner layer and the heat insulation outer layer within the optimum range.

By using a vacuum heat insulating container as the internal container, it is possible to further lower the temperature reached in the logger storage container (see Examples 3 and 4). In addition, while setting the value of “d ₁ / (d ₁ + d ₂ )” within the range of 0.6 to 0.7 and using a vacuum heat insulating container, the temperature reached in the logger storage container is set to It is clear that the maximum reduction is possible (see Example 4).

  The heat insulation container for temperature measurement of the present invention is compact while having excellent heat insulation performance. Therefore, the temperature measurement thermal insulation container of the present invention is assumed to be used for a long time in a limited space, in various continuous furnaces such as a ceramic firing continuous furnace and a food manufacturing furnace. It is suitable as a heat insulating container for constituting a temperature measuring device that is used by being moved in a continuous furnace together with the object to be processed.

It is sectional drawing which shows typically one Embodiment of the heat insulation container for temperature measurement of this invention. It is sectional drawing which shows typically one Embodiment of the conventional heat insulation container for temperature measurement. It is sectional drawing which shows typically the planar model for unsteady heat-transfer calculation. It is a graph which shows the result of unsteady heat transfer calculation using a plane model. It is sectional drawing which shows typically the cylindrical shape model for unsteady heat transfer calculation. It is a graph which shows the result of unsteady heat transfer calculation using a cylindrical shape model. It is a graph which shows the result of unsteady heat transfer calculation using a cylindrical shape model. It is the graph which plotted the temperature (degreeC) in a logger storage container with respect to time (h).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,10: Thermal insulation container for temperature measurement, 2: Logger storage container, 3: Thermal storage inner layer, 4: Thermal insulation outer layer, 5: Logger, 6: Temperature sensor, 8, 38: Space to be insulated, 11: Ice water, 12: Inside Container, 13: Low thermal conductivity material, 14: Support base, 15: Lid, 23: Inner layer, 24: Outer layer, 25: Plane model, 35: Cylindrical model, 37: Center axis, d ₁ : Thickness of heat storage inner layer , D ₂ : thickness of the heat insulating outer layer, D: thickness of all layers, R _i : heat-insulated space radius, T ₁ : internal temperature, T ₂ : external temperature

Claims (4)

A logger storage container capable of storing a logger for recording temperature data;
A heat storage inner layer disposed outside the logger storage container and filled with ice water;
An insulated container for temperature measurement, comprising: an inner container disposed outside the heat storage inner layer and filled with the ice water; and a heat insulating outer layer including a low thermal conductivity material disposed outside the inner container. The logger storage container is disposed substantially at the center,
To the total of the heat storage inner layer thickness _{(d 1)} and the thermal insulation layer of thickness _{(d 2),} the ratio of the values of the thermal storage layer of the thickness _{(d 1) (d 1 /} (d 1 + d 2)) is, 0 The insulated container for temperature measurement according to claim 1, which is in a range of .6 to 0.7.   The temperature measurement heat insulation container according to claim 1 or 2, wherein the inner container is a vacuum heat insulation container.   The said low thermal conductivity material is at least 1 type selected from the group which consists of ceramic fiber, glass wool, rock wool, a calcium silicate heat insulating material, and a microporous structure heat insulating material, The Claim 1 any one of Claims 1-3. Insulated container for temperature measurement.

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