JPH08219620A - Convection type observation see-through structure - Google Patents

Abstract

PURPOSE: To provide an observation see-through structure which can be applied to a device of which the temperature/humidity varies depending on the using state, and which can easily and totally prevent a condensation from generating because a convection generates without fail. CONSTITUTION: An observation see-through structure is constituted of an external glass 1, internal glass 2, intermediate glass 3, spacer 4, lower notch 7 which is provided on the intermediate glass, upper notch 8, heater 9 and internal and external temperature sensors 11, 10. By this constitution, when the temperature of a test room 102 is low, heated air ascends in a space 5, and descends after being cooled in a space 6, and a natural convection is formed, and the heater 9 is controlled by the temperature sensor 10, and the external surface of the external glass 1 becomes the same temperature as the outside air, and a condensation on the surface is prevented from generating. When the inside of the test room is hot and humid, the test room side of the internal glass 2 becomes the same temperature as the test room, and a condensation on the surface is prevented from generating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent structure formed by arranging an intermediate transparent plate between an outer transparent plate and an inner transparent plate, and more particularly to a technique for preventing dew condensation.

[0002]

2. Description of the Related Art A transparent structure in which an intermediate transparent plate is arranged between inner and outer transparent plates to form a multi-layered structure to provide heat insulation is a low temperature or high temperature inside an environment tester, refrigerator, showcase, etc. It is used for the observation window and door of the container. Further, in such a see-through structure, there is a risk that dew condensation may occur on the inner and outer surfaces of the transparent plate due to the temperature difference between the inner and outer parts, and therefore various measures have been taken to prevent this. Among them, as a method of preventing dew condensation with a simple structure, there is a method using air convection. For example, the widths of the spaces on both sides of the intermediate transparent plate are made different, and the heater is arranged on the wide side to generate convection to heat the glass surface so that convection does not occur on the narrow side. The transparent structure described above has been proposed (see Japanese Patent Laid-Open No. 2-136670).

However, such a see-through structure is
It can only be applied to devices such as refrigerators and low temperature showcases where the side where convection does not occur is always low temperature. Further, in a space where there is no partition and the width is simply set to a specific dimension, the generation of convection and the prevention of convection are likely to be incomplete.

[0004]

The present invention solves the above-mentioned problems in the prior art and can be applied to an apparatus such as an environmental test apparatus in which the temperature and humidity conditions vary, and convection is surely generated. An object is to provide a see-through structure capable of easily and completely preventing dew condensation.

[0005]

In order to solve the above-mentioned problems, the present invention provides a perspective structure in which an intermediate transparent plate is arranged between an outer transparent plate and an inner transparent plate. The one end side and the other end side opposite to the one end side opening and the other end side opening, which are provided so as to electrically connect the space portions on both sides of the intermediate transparent plate, respectively, and are arranged in the vicinity of the one end side opening. And a heating element for generating heat.

[0006]

According to the present invention, in the transparent structure, the intermediate transparent plates are arranged between the inner and outer transparent plates, the openings are provided at both end sides of the intermediate transparent plate, and the heating element is arranged near the one end side opening. Since the inner transparent plate is on the test chamber side of the environmental testing device and one end side is on the lower side, and the transparent structure is used for the door or the window, it is possible to prevent dew condensation and has heat insulating properties. It becomes a door or a window. That is, although gas such as air exists between the inner and outer transparent plates, for example, when the temperature in the test chamber becomes low, the gas in the space on the test chamber side partitioned by the intermediate transparent plate is cooled and becomes low temperature. , The gas in the space on the outside world becomes room temperature, which is close to the temperature of the outside world, and the difference in specific gravity occurs due to the temperature difference between the gases on both sides. Then, the natural convection occurs due to the flow from the low temperature side to the normal temperature side. Then, when a heating element provided near the lower opening is made to generate heat, the heated gas rides on natural convection to rise on the normal temperature side, flow to the low temperature side and descend, and continuously form natural convection. While heating the outer transparent plate. In this case, since the intermediate transparent plate serves as a partition, this natural convection is surely generated, so that the outer transparent body is surely heated, and the dew condensation on the outer side surface is surely prevented.

On the other hand, when the test chamber is in a high temperature and high humidity environment, natural convection occurs in the opposite direction to the above. As a result, the inner transparent plate is heated by the gas heated by the heating element, and the dew condensation inside the tank is reliably prevented. If the temperature of the test room is low, the temperature of the side surface of the space inside the transparent plate will also be low to some extent.Therefore, fill the space with dry air or inert gas with a low dew point or add a desiccant. It is desirable to dehumidify and keep the gas in the space to be a gas with a low dew point.

[0008]

EXAMPLE FIG. 1 shows a structure of a see-through structure according to an example. The transparent structure is formed by arranging an intermediate glass 3 which is an intermediate transparent plate between an outer glass 1 which is an outer transparent plate and an inner glass 2 which is an inner transparent plate. A spacer 4 is interposed between the inner and outer glass and the intermediate glass, and these are integrally joined. The intermediate glass 3 is provided below one end of the intermediate glass and above the other end thereof, respectively.
A lower cutout 7 and an upper cutout 8 are provided in the intermediate glass 2 as one end side opening and the other end side opening for connecting the space portions 5 and 6 on both sides of An electrothermal heater 9 is provided as a heating element for generating the. In this embodiment, an outer temperature sensor 10 and an inner temperature sensor 11 for detecting the temperature are further attached to the surfaces of the outer and inner glasses, and the heater 9 is controlled to be turned on / off. Also, the space parts 5 and 6 are sealed,
Dry air having a dew point of about −20 ° C. is enclosed as a low dew point gas inside.

Such a see-through structure is used, for example, as a sliding door of the environmental testing device 100, and the outer glass 1
Is attached so that the outer glass 101 faces the outside world 101 and the inner glass 2 faces the test chamber 102 side. In the environmental test equipment, low-temperature operation and high-temperature and high-humidity operation are performed.
When the temperature is as low as 0 ° C, the relative humidity is 9 ° C at 60 ° C.
The temperature and humidity are set to about 0%. The transparent structure does not necessarily have to be provided vertically, and may be attached to an appropriate inclined surface so as to be compatible with a device to which the transparent structure is mounted, such as an environmental test device.

FIG. 2 shows the state of natural convection of air in the transparent structure of the present invention, and (a) and (b) show the above low temperature operation and high temperature and high humidity operation, respectively. If the environmental test equipment is installed in the factory and the temperature of the external environment 101 rises to about 25 ° C. as the ambient condition, a considerable temperature difference occurs between the external environment side and the test room side during low temperature operation, so that the space is reduced. A difference in specific gravity occurs in the air in the parts 5 and 6 due to the temperature difference, and the gas inside is naturally convected in the direction shown by the arrow in FIG. During such a low temperature operation, the outer temperature sensor 10 operates and controls the heater 9 so that the temperature of the outer surface of the outer glass 1 becomes substantially the same as the predetermined temperature of the outside world. According to such natural convection, the outer glass 1 is easily and uniformly heated, and the temperature of the outer surface thereof is 25 °.
It can be maintained at about C. As a result, for example, even if the relative humidity of the outside world is about 80% and the dew point is about 20 ° C, it is possible to reliably prevent the dew condensation on the outside side surface of the outer glass 1. Further, since the low dew point gas is enclosed in the space portions 5 and 6, dew condensation does not occur even on the space portion 6 side of the inner glass 2. According to such an operation, the temperature distribution as illustrated is formed in each part of the transparent structure.

During high-temperature and high-humidity operation, air convection naturally occurs in the direction indicated by the arrow (b), which is the opposite of FIG. 2 (a). At this time, the heater 9 is controlled so that the temperature of the surface of the inner glass 2 on the test chamber 102 side detected by the inner temperature sensor 11 becomes the same as the temperature in the test chamber. As the temperature in the test chamber, for example, the set temperature in the environmental test device is used. As a result, the surface of the inner glass on the test chamber side does not fall below the dew point temperature, and dew condensation on this surface is reliably prevented.

In the above, the selection of which of the sensors 11 or 12 to control the heater 9 is made by determining whether the operation is low temperature or high temperature according to the set temperature of the test chamber, or whether the temperature of the sensors 11 or 12 is controlled. This is done by prioritizing the higher one. However, it is not always necessary to control the heater 9 by the sensors 11 and 12 in this way. For example, from the temperature and humidity conditions such as low temperature operation and high temperature and high humidity operation, it is possible to prevent dew condensation under any operating condition.
Output may be determined, and this may be constantly operated or turned on / off at predetermined intervals. In this case, when the speed of natural convection increases, the heat that enters the test chamber 101 increases, and when the speed of natural convection decreases, the outside glass 1
Since the temperature of the upper portion of the notch does not rise easily, it is necessary to determine the size of the notch 8 so that natural convection occurs at an appropriate speed. Further, a suitable member such as a damper or a baffle plate capable of adjusting the passage cross-sectional area may be provided in the notch 8 or the space portion 6.

In the above description, the heater 9 is arranged directly below the intermediate glass 3 as shown in FIG. 1, but it is not always necessary to arrange it in this position, and for example, it may be arranged in the bottom of the space 5 side. . Even in that case, when operating at high temperature,
Since the natural circulation system of air as shown in (b) is formed, the test chamber side of the inner glass 2 can be heated to a target temperature. If the heater 9 is arranged at the bottom of the space 5 side, the space for arranging the heater becomes wider, and
Since the position of the heater is far from the test chamber, heat transfer from the heater toward the test chamber during low temperature operation can be reduced. Further, in the above, an example in which the transparent structure is applied to an environmental test device has been described, but the transparent structure of the present invention is applied to a device which is always low in temperature such as a refrigerator or a low temperature showcase, or for plant cultivation. It can also be applied to devices such as greenhouses that maintain high humidity and buildings.

FIG. 3 shows an example of the transparent structure in which the intermediate glass is arranged in two layers. In this way, the intermediate glass is 3-
If the layers 1 and 3-2 are provided in two layers, heat transfer between the inside and the outside can be further reduced. In this transparent structure, during high-temperature high-humidity operation or low-temperature operation, the heaters 9-1 and 9 form a natural circulation system of air as shown in (a) and (b), respectively. The outside world or the test room side of 2 is heated to the temperature inside the outside world or the test room. In any case, dew condensation on each surface is prevented.

FIG. 4 shows a case where the transparent structure has a circular shape. In this case, the notches 7 and 8 are provided in an arc shape, and the heater 9 is also arranged in an arc shape. Even with such a perspective structure,
As in the case of FIG. 1, natural convection of air can be generated and dew condensation on the glass surface can be prevented during low temperature operation and high temperature and high humidity operation. Such a circular transparent structure is conveniently used for a door of a cylindrical thermostatic chamber, a window of an environmental testing device, and the like.

FIG. 5 shows an example of a see-through structure having two layers of intermediate glass and a heat insulating space formed therebetween. This transparent structure has a space 12 for heat insulation formed by providing intermediate glass 3-1 and 2-2 in two layers and inserting a spacer 4'between them. It is desirable that the space 12 is evacuated, but air having a somewhat low dew point may be enclosed. Even in such a structure, (a)
When the test chamber 102 side shown in (1) and (b) is low temperature and high temperature and high humidity, natural convection of air as indicated by an arrow is obtained, and dew condensation on the glass surface can be prevented. According to this structure, since the heat insulating property of the intermediate glass portion is high, it is possible to reduce the amount of air that naturally circulates and reduce the heat input and output between the external environment 101 and the test chamber 102.

[0017]

As described above, according to the present invention, an opening is provided at both ends of the intermediate transparent body, and a heating element is provided in the vicinity of the one end side opening arranged below, so that the transparent structure can be subjected to, for example, an environmental test. Even when installed in a device such as a device that can perform either low temperature operation or high temperature and high humidity operation depending on the selection, natural circulation is generated and either the inner or outer transparent body, whichever has the higher temperature, is installed. It is possible to reliably heat the transparent body and reliably prevent dew condensation on the outer surface thereof. In addition, such a see-through structure has an opening and a heating element as compared with a normal structure, and therefore has a very simple structure.

[Brief description of drawings]

FIG. 1 shows a structure of a see-through structure according to an embodiment, (a) is a sectional view and (b) is a side view.

FIG. 2A and FIG. 2B are explanatory views of the operation of the transparent structure.

FIG. 3 is a cross-sectional view showing the structure of a see-through structure according to another embodiment, and FIGS. 3 (a) and 3 (b) show states in which the test chamber is at high temperature and high humidity and at low temperature, respectively.

FIG. 4 shows a structure of a transparent structure of another embodiment, (a)
Is a sectional view and (b) is a side view.

FIG. 5 is a cross-sectional view showing a structure of a see-through structure according to still another embodiment, and FIGS. 5 (a) and 5 (b) respectively show states in which the test chamber is at high temperature and high humidity and at low temperature.

[Explanation of symbols]

 1 Outer Glass (Outer Transparent Body) 2 Inner Glass (Inner Transparent Body) 3, 3-1, 3-2 Intermediate Glass (Intermediate Transparent Body) 5, 6 Space 7 Lower Cutout (One End Side Opening) 8 Upper Cut Notch (opening on the other end) 9 Heater (heating element)

Claims (1)

[Claims] 1. A transparent structure formed by arranging an intermediate transparent plate between an outer transparent plate and an inner transparent plate, wherein the intermediate transparent plate is provided on one side of the intermediate transparent plate and on the other side thereof opposite thereto. One end side opening and the other end side opening provided so as to electrically connect the space portions on both sides of the plate, and a heating element arranged near the one end side opening for generating heat are characterized in that Perspective structure.