JP2003194481A - Inspection window with heater for preventing dew condensation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection window with a heater for preventing dew condensation allowing the inside of a furnace to be monitored without stopping the furnace to open the inspection window or cleaning glass panes by restraining waterdrops from sticking to the glass pane surface of a viewport by dew condensation. <P>SOLUTION: In this inspection window with the heater for preventing dew condensation, the viewport 5 of an inspection window 4 provided for monitoring the inside of the furnace is constituted placing two glass panes in layers, and a heat retaining heater 6 is mounted between two glass panes 2, 3. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-temperature heating furnace for heat-treating electronic parts, ceramic products, etc., for example, a furnace for supplying a humid gas to form an atmosphere in the furnace. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection window for preventing deterioration of visibility due to dew condensation as a viewing window of an inspection port for monitoring the inside of a furnace in a ceramic firing electric furnace or the like that forms an internal atmosphere. 2. Description of the Related Art In order to maintain an atmosphere in a furnace, an electric furnace for firing a ceramic in which an atmosphere is formed in a furnace with a specific gas is usually constituted by a highly airtight muffle or the like at the entrance and exit of the furnace. I have. Therefore, it is very difficult to inspect the inside of the furnace without dismantling the muffle. For this reason, an inspection port for monitoring the inside of the furnace is provided, and the condition inside the furnace is monitored from a viewing window of the inspection port. FIG. 3 is a cross-sectional view illustrating a conventional inspection window. In FIG. 3, an inspection window 1 has an inspection port 4 provided at an appropriate position for monitoring the inside of the furnace and an inspection port 4 for observing the inside of the furnace. The inspection port 4 and the glass plate 2 are formed in close contact with a rubber packing 7 and are kept airtight. However, when the gas supplied for forming the atmosphere in the furnace has a high dew point, the temperature difference between the inside 8 of the furnace having a high temperature and the outside 9 of the furnace (inside of the room) having a low temperature causes the surface of the glass sheet 2 to be reduced. Water drops due to dew condensation on the inside of the furnace and the glass plate becomes cloudy, making it impossible to see through the furnace, making it virtually impossible to monitor the inside of the furnace and causing problems in operation and quality control. There is. Further, there is also a problem that the attached water drops fall on the article to be heat-treated and deteriorate the product quality. Therefore, cleaning of the inspection window 1 stops the furnace,
The glass plate 2 must be cleaned by opening the inspection port 4, and there is a problem that the shutdown of the equipment and the destruction of the furnace atmosphere occur, and the furnace operation efficiency is reduced. The inventor of the present invention has conducted intensive studies to solve these problems, and has used two glass plates for the inspection window, and provided a glass plate between the glass plates. It was confirmed that by attaching a heater and maintaining the temperature of the glass plate surface at a temperature equal to or higher than the dew point of the atmosphere gas in the furnace, dew condensation on the glass plate surface could be effectively suppressed. That is, an object of the present invention is to solve the above-mentioned problems and to suppress the generation of water droplets adhering to the glass plate surface of the viewing window due to condensation, thereby stopping the furnace and opening the inspection window. It is an object of the present invention to provide an inspection window with a heater for preventing dew condensation, which can constantly monitor the inside of the furnace without having to clean the glass plate. [0008] In order to achieve the above object, an inspection window 1 with a heater for preventing dew condensation according to the present invention is a viewing window 5 of an inspection port 4 provided for monitoring inside the furnace. Is constituted by stacking two glass plates, and a heater 6 for keeping heat is attached between the two glass plates 2 and 3. FIG. 1 is a cross-sectional view illustrating an inspection window with a heater for preventing dew condensation according to the present invention, and FIG. 2 is a plan view thereof. In FIG. 1, 1 is an inspection window with a heater for preventing dew condensation,
Reference numerals 2 and 3 denote two stacked glass plates constituting a viewing window 5 of the inspection port 4. Reference numeral 6 denotes a heater for heat retention attached between the glass plates 2 and 3, reference numeral 7 denotes a rubber packing for tightly contacting the inspection port 4 and the viewing window 5, reference numeral 8 denotes the inside of the furnace (high-temperature portion), and reference numeral 9 denotes the furnace. The outside (low temperature part) is shown. The inspection port 4 is installed at a position suitable for monitoring the inside of the furnace.
Monitor through 3. During furnace operation, the inside 8 of the furnace is exposed to the high temperature inside the furnace, while the outside 9 of the furnace is significantly lower in temperature than the inside of the furnace. In the following, dew condensation occurs on the surface of the glass plate, and water droplets are generated and adhere. According to the present invention, the glass plate is heated by a heat retaining heater 6 mounted between the glass plates 2 and 3, and is heated and maintained at a temperature not lower than the dew point of the atmosphere gas in the furnace. This is to prevent condensation. The heater 6 for heating is preferably capable of heating and holding at about 100 to 150 ° C., and for example, an electric heater or a metal sheath type heater coated with silicon rubber is preferably used. FIG. 2 shows that the heat retaining heater 6 is connected to the glass plates 2 and 3.
FIG. 2 is a plan view of the inspection window with a heater for preventing dew condensation schematically illustrating a state where the heater is attached between the heaters, and it is preferable that the heater for heat retention 6 be disposed and attached at a position where it does not hinder monitoring in the furnace. In addition, the heater 6 for heat retention can be used by being embedded in the glass plate 2 or 3 in advance. As described above, the inspection window 1 with the heater for preventing dew condensation according to the present invention has the observation window 5 formed by stacking the two glass plates 2 and 3, and the atmosphere in the furnace is provided between the glass plates 2 and 3. A heater 6 for keeping the temperature above the dew point of the incoming gas for forming is attached, and the glass plate is heated and maintained at a temperature above the dew point of the incoming gas by the heater during furnace operation. Thus, dew condensation on the glass plate surface can be effectively prevented. When the inspection window 1 with a heater for preventing dew condensation is applied during operation of the furnace, the inspection window 5 is maintained while maintaining the furnace atmosphere.
It is possible to monitor the inside of the furnace without cleaning the glass plates 2 and 3 of the above.Conventionally, dew condensation occurred on the glass plate in a few days, making it difficult to monitor the inside of the furnace. It was possible to monitor the inside of the furnace without condensation. As described above, according to the inspection window with a heater for preventing dew condensation of the present invention, while maintaining the atmosphere in the furnace, the inspection window is formed on the glass plate of the viewing window due to the temperature difference between the inside of the furnace and the outside of the furnace. Dew condensation can be effectively prevented, and the furnace can be monitored for a long time without opening the inspection window and cleaning the glass plate of the viewing window. Therefore, the operation stability of the high-temperature heating furnace is improved, and the deterioration of the quality of the heat-treated product due to the drop of the condensed water droplets is suppressed, so that the furnace can be operated efficiently.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view illustrating an inspection window with a heater for preventing dew condensation according to the present invention. FIG. 2 is a plan view of an inspection window with a heater for preventing dew condensation, schematically illustrating a state in which a heater for keeping heat is attached between glass plates. FIG. 3 is a cross-sectional view illustrating a conventional inspection window. [Explanation of Signs] 1 Inspection window with heater for preventing dew condensation 2 Glass plate 3 Glass plate 4 Inspection port 5 Peep window 6 Heating heater 7 Rubber packing 8 Inside of furnace (high temperature section) 9 Outside of furnace (low temperature section)

Claims (1)

Claims: 1. An inspection window 5 of an inspection port 4 provided for monitoring the inside of a furnace is constituted by laminating two glass plates, and between the two glass plates 2, 3. Inspection window 1 with a heater for preventing dew condensation, wherein a heater 6 for keeping heat is attached.