JP2001330277A - Constant temperature constant humidity device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a constant temperature constant humidity device to reduce a consumption amount of pure water by recovering and re-utilizing pure water in humidified steam, though pure water for a humidifier is wasted since humidified steam generated by a humidifier during control of humidity is discharged to the outside of a test tank due to a pressure difference between the inside and the outside of the test tank. SOLUTION: In the constant temperature constant humidity device provided at the inside of the test tank 1 with a heater 7, the humidifier 3, and a cooler 8, during working of the humidifier 3, humidified steam discharged through an equalizing opening 2 is cooled by a condensation pipe 4 connected to the equalizing opening 2 and extending downward. Pure water condensed on the inner wall of the condensing pipe 4 is recovered in a water-receiving tank 5 and re-utilized for humidifying effected at the humidifier 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant-temperature and constant-humidity apparatus for maintaining the inside of a test tank at constant temperature and constant humidity and performing an environmental test of electronic parts, electronic equipment, resin molded products, foods and chemicals, and the like. More particularly, the present invention relates to a thermo-hygrostat suitable for reducing consumption of pure water used for controlling humidity in a test tank.

[0002]

2. Description of the Related Art In a constant-temperature and constant-humidity apparatus, humidification may be performed by a humidifier in order to control the humidity in a test tank to a predetermined value. In general, the amount of water to be controlled in the humidifier is controlled by a water level detector installed outside the test tank. It is difficult to detect a correct water level when a pressure difference occurs inside and outside the test tank. In addition, the function of the thermo-hygrostat requires that the door be opened and closed during operation and shutdown, and the pressure inside and outside the test chamber is balanced to avoid sudden blowing of humidified steam when the door is opened. A pressure equalizing port is required in the test tank to maintain the pressure.

As the supply water for humidification, it is common to use pure water produced with a very small amount of impurities in a pure water production device so that impurities do not accumulate in the test tank. When the internal pressure is high, the humidified steam humidified by the humidifier is discharged from the pressure equalizing port to the outside of the test tank. Conventionally, the discharged humidified steam was released into the atmosphere as it was, so pure water contained in the humidified steam was also released into the atmosphere, and the test object placed in the test tank was tested. In order to control the temperature and humidity in the tank, and in particular to perform the test continuously for a long time, it was necessary to periodically supply pure water.

An example of a water supply / drainage system of a constant temperature and humidity apparatus is disclosed in Japanese Patent Application Laid-Open No. 1-167540. In this example, the drainage system of the pure water also serves as the pressure equalizing port, and the pure water contained in the humidified steam is discharged from the drainage system.

[0005]

As in the prior art described above, regular replenishment of pure water is indispensable in order to continuously perform tests using a thermo-hygrostat. The pure water is stored in a portable tank, and when the pure water in the tank becomes lower than the predetermined value, the tank is removed from the constant temperature and humidity device each time, and pure water is separately supplied to the tank from the pure water production device. It is necessary for the tester to carry out the work of filling the tank and attaching the tank to the thermo-hygrostat again. Therefore, the test practitioner must transport the tank each time pure water is consumed, which requires considerable effort in a continuous long test.

[0006] If the tester neglected the above-mentioned operation, the constant temperature and humidity apparatus could not control the humidity in the test tank when the pure water in the tank was exhausted. Has to be interrupted.

[0007] Some test sites are configured so that pure water can be automatically replenished with the consumption of pure water by connecting a pure water producing device and a constant temperature and humidity device. The rise in equipment costs, such as the installation of water supply piping equipment and a pure water production device with a capacity corresponding to the amount of pure water consumed, poses a problem.

In view of the above problems, an object of the present invention is to provide a constant temperature and humidity apparatus having a pure water condensing / recovering means for reducing the consumption of pure water during a test.

[0009]

Means for Solving the Problems In order to achieve the above object, a constant temperature and humidity apparatus according to the present invention has the structural features as described in claims 1 to 6. In particular, the temperature and humidity control apparatus according to claim 1 as an independent item includes a temperature and humidity control unit including a fan and a humidifier in the test tank, and the test tank is provided in the temperature and humidity control unit. In a constant temperature and humidity apparatus provided with a pressure equalizing port communicating the inner space with the outer space, a pure water supply system including a tank for supplying pure water, a drainage system, and various instrumentation, the test is performed by connecting to the pressure equalizing port. The apparatus is characterized in that a condensing means for the pure water discharged from the tank is provided, and a collecting means for collecting the pure water condensed by the condensing means is provided.

[0010]

FIG. 1 is a diagram showing a first embodiment. The test tank 1 of the thermo-hygrostat comprises a thermo-humidity controller 15 divided by a partition plate 14 and a test chamber 16.

The temperature and humidity control unit 15 includes a humidifier 3, a heater 7 and a cooler 8, and controls the temperature and humidity of the test room 1.
6 is provided with an in-tank fan 6 for transferring to the tank 6. The instrumentation includes a thermometer, a hygrometer, a water level detector, and the like, and has a water supply system, a drainage system, and the like as incidental facilities. A condensing pipe 4 as a condensing means is connected and extended downward from a pressure equalizing port 2 for keeping the pressure inside and outside the test tank 1 of the thermo-hygrostat constant.
Pure water is condensed and recovered while the humidified steam discharged from the pressure equalizing port 2 passes through the condenser tube 4.

In the constant temperature and humidity apparatus, the air in the test tank 1 is circulated by the fan 6 in the tank, and the heater 7 and the cooler 8 are operated as necessary to control the temperature in the test tank 1. The humidity in the test tank 1 is controlled by operating the humidifier 3 and the cooler 8. Here, when the humidifier 3 operates and the pressure in the test tank 1 becomes higher than the pressure outside the test tank 1, the humidified steam generated in the humidifier 3 is discharged from the equalizing port 2 to the outside of the test tank 1, and the condensing pipe When the humidified steam comes into contact with the inner wall of the condenser tube 4 and is cooled to a temperature lower than the dew point, pure water contained in the humidified steam is condensed. Condensation forms on the inner wall of the tube 4 to form water droplets.

The pure water which has become water droplets falls due to gravity and enters a water receiving tank 5 as a collecting means provided immediately below the tip of the condenser tube 4. If the pure water that has entered the water receiving tank 5 is provided in advance with a tank for supplying pure water (not shown) or a water supply path for introducing the pure water into the humidifier 3, the humidifier 3 can be returned again.
Pure water was collected because it could be used for humidification at

If necessary, the condenser tube 4 is forcibly cooled by a blower 9 or the like as shown by a dotted line in FIG. 1, or the condenser tube 4 is formed as a double tube and cooled by cooling water or the like. As a result, more pure water is condensed on the inner wall of the condensing tube 4, and the pure water recovery efficiency can be improved.

FIG. 2 is a diagram showing a second embodiment. A heat transfer tube 10a of a heat exchanger 10 as a condensing means is provided at a pressure equalizing port 2 for keeping the pressure inside and outside a test tank 1 of a constant temperature and humidity apparatus at equilibrium.
And the humidified steam discharged from the pressure equalizing port 2 is introduced into the heat exchanger 10 to recover pure water contained in the humidified steam.

As in the case of the first embodiment in which the condenser tube 4 of FIG. 1 is installed, the pure water contained in the humidified steam is supplied to the heat exchanger 1.
The heat is cooled to a temperature lower than the dew point in the inside of the heat exchanger 10 and condensed, and is once collected in a water receiving tank 5 as a collecting means provided immediately below the heat transfer tube 10a of the heat exchanger 10. The fact that pure water collected in the water receiving tank 5 is guided to a tank for supplying pure water or to a water supply path for introducing pure water into the humidifier 3 means that pure water is collected in the first case. This is the same as the embodiment.

The heat exchanger 10 may be simply cooled by a natural heat radiator or a blower 9. However, the heat exchanger 10 may be connected to the refrigerator 11 as shown by a dotted line in FIG. A large amount of pure water is condensed inside the heat exchanger 10, and the efficiency of collecting pure water can be improved.

FIG. 3 is a diagram showing a third embodiment. In the first and second embodiments, the pure water condensed in the condenser tube 4 and the heat exchanger 10 is once collected in the water receiving tank 5, but these pure water is already provided in the constant temperature and humidity apparatus. The supply tank 12 itself may be directly collected as the water receiving tank 5. FIG. 3 shows a water receiving tank 5 according to the first embodiment.
An embodiment in which the pure water supply tank 12 itself is used as the water receiving tank 5 instead of the water supply tank 5 will be described.

As shown in FIG. 3, a condensing tube 4 as condensing means
The pure water condensed on the inner wall of the tank is partially collected by the condenser 12 and directly collected in the tank 12 as the collecting means, thereby simplifying the path structure of the pure water supply system and the collecting system, Pure water coming out of the condenser tube 4 in a state of humidified steam without dew condensation is also condensed by contacting the pure water stored in the tank 12 and collected in the tank 12. It is possible to further improve the collection efficiency.

FIG. 4 is a diagram showing a fourth embodiment. As an example for simplifying the path structure of the pure water supply system and the recovery system, an embodiment in which pure water condensed in the condensation tube 4 or the like is directly returned to the humidifier will be described.

When the condenser pipe 4 is connected to the pressure equalizing port 2 so as to be higher than the pressure equalizing port 2, pure water condensed on the inner wall of the condenser pipe 4
Since the water flows downward by gravity and returns to the humidifier 3, pure water can be recovered only by installing the condenser tube 4, and the path structure of the pure water supply system and the recovery system can be simplified. In this case, the condensing tube 4 is forcibly cooled by the blower 9 or the like as shown in the first embodiment, or the heat exchanger 10 is connected as shown in the second embodiment. Further, the recovery efficiency of pure water can be improved.

FIG. 5 is a diagram showing another embodiment. In the first to fourth embodiments, various devices are connected to the pressure equalizing port 2 for keeping the pressure inside and outside the test tank 1 at equilibrium, and pure water is collected. The case where the pressure inside the tank 1 is higher than the pressure outside the test tank 1 is described. Conversely, when the pressure inside the test tank 1 is lower than the pressure outside the test tank 1, the humidified steam is not discharged from the pressure equalizing port 2, so that no pure water is consumed. 1, it becomes difficult to control the temperature and humidity in the test tank 1, and there is a possibility that the purpose as a constant temperature and humidity apparatus for keeping the temperature and humidity in the test tank 1 constant may not be achieved.

To prevent this, as shown in FIG. 5, a motorized valve 13 is installed in the condenser tube 4 and a control device 17 for controlling the motorized valve 13 is installed. If it is higher, the motor-operated valve 13 is opened.
You only have to close 3. Further, a check valve may be provided in place of the motor-operated valve 13 to prevent air outside the test tank 1 from flowing into the test tank 1.

[0024]

By applying the pure water condensing / recovering means according to the present invention to a thermo-hygrostat, the consumption of pure water becomes very small even in a continuous long-time test. The labor of the tester who monitors the consumption and supplies pure water as needed can be greatly reduced.
In addition, since a long-term test can be performed using the constant-temperature and constant-humidity device alone, equipment costs can be reduced even at a test site where an automatic water supply system has been introduced in the past.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a second embodiment of the present invention.

FIG. 3 is a schematic diagram showing a third embodiment of the present invention.

FIG. 4 is a schematic diagram showing a fourth embodiment of the present invention.

FIG. 5 is a schematic view showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Test tank 2 ... Equalizing port 3 ... Humidifier 4 ... Condenser tube 5 ... Water receiving tank 6 ... Tank fan 7 ... Heating device 8 ... Cooler 9 ... Blower 10 ... Heat exchanger 10a ... Heat transfer tube 11 ... Refrigerator DESCRIPTION OF SYMBOLS 12 ... Tank 13 ... Electric valve 14 ... Partition plate 15 ... Temperature control and humidity control unit 16 ... Test room 17 ... Control device

Continued on the front page (72) Inventor Kazuhiro Matsushita 390 Muramatsu, Shimizu-shi, Shizuoka Prefecture Within Hitachi Shimizu Engineering Co., Ltd. (72) Inventor Yasuo Kawamoto 390 Muramatsu, Shimizu-shi, Shizuoka Prefecture F-term in Hitachi Shimizu Engineering Co., Ltd. (Reference) 3L048 AA01 BA01 CA06 CB02 DA01 3L054 BE01

Claims (7)

[Claims] 1. A test chamber having a temperature control and humidity control unit including a fan and a humidifier in the test chamber, wherein the temperature control and humidity control unit includes an equalizing port for communicating the space inside the test tank with an external space. In a constant temperature and humidity apparatus provided with a pure water supply system including a pure water supply tank, a drainage system, and various types of instrumentation, a condensing means connected to the equalizing port and discharging pure water discharged from the test tank is provided. A constant-temperature and constant-humidity device provided with a collecting means for collecting pure water condensed by the condensing means. 2. The constant temperature and humidity apparatus according to claim 1, wherein the condensation means is a condensation tube connected to the pressure equalizing port and extending downward outside the test tank. 3. A heat exchanger is provided outside the test tank, and the condensing means is a heat transfer tube of the heat exchanger connected to the pressure equalizing port and extending downward. The constant temperature and humidity apparatus according to claim 1. 4. The condensing means is a condensing pipe connected to the pressure equalizing port and extending upward outside the test tank, so that pure water condensed in the condensing pipe returns to the humidifier by gravity. The constant temperature and humidity apparatus according to claim 1, wherein: 5. The constant temperature and humidity apparatus according to claim 1, wherein the collecting unit is a water receiving tank configured to receive condensed pure water. 6. The constant temperature and humidity apparatus according to claim 1, wherein the pure water supply tank itself is a collecting unit for collecting the condensed pure water. 7. An electric valve or a check valve which closes when the pressure in the outer space of the test tank is higher than the pressure in the inner space, is provided in the condensing means. A constant temperature and humidity apparatus according to any one of the above.