JPH0416053Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a high-temperature pressure vessel containing a material with high vapor pressure.

[Conventional technology]

Among high-temperature pressure containers that generally contain materials with high vapor pressure either directly or after being sealed in ampoules, those of the internal heating type, that is, those with a heating heater inside the container, are shown in Figure 2a. It has a cross-sectional structure like this. That is, the container body 1 is made of high-pressure stainless steel and has a cylindrical shape, and inside thereof a heater 2 wound around a furnace core tube is surrounded by a heat insulating material 3. The heater 2 usually employs a 2- or 3-zone system in order to make the heating range as long as possible. Lead wires from the heater and thermocouple for temperature control are drawn out through the electrical terminal group 4, and further,
Cover 5 to prevent the increased pressure inside the container from leaking to the outside.
is fixed and sealed with several bolts 6. The temperature distribution of the furnace core due to the heater 2 is as shown in FIG.

[Problem that the invention attempts to solve]

As the heat insulating material 3, a quartz tape made of quartz glass fibers is generally used, and by wrapping this tape around the heater 2 in multiple layers, it fills the gap with the container wall and retains heat. Quartz tape has low thermal conductivity, so it has excellent heat retention, and its high flexibility makes it easy to handle, making it a useful material as a heat insulator. However, quartz is highly hygroscopic, as is well known for its hygroscopic material, silica gel. For this reason, quartz tape used when installing a new furnace or replacing a heater absorbs moisture, and even if it has been used several times, it is exposed to air when the furnace is not in operation, so it cannot be exposed to air. absorbs moisture. This moisture begins to evaporate when the temperature of the heater rises during operation of the furnace, but since the inside of the furnace is sealed as described above, it cannot escape to the outside and is trapped in the upper space 7 of the pressure vessel. Stay. and,
Since the inner wall of the container surrounding this area is a low-temperature area where almost no heat from the heater reaches, water vapor adheres to the inner wall and becomes water droplets. The water droplets eventually descend along the inner wall and reach the inside of the furnace in terminal group 4, but since water is conductive, it electrically shorts the terminals together, so it can melt the power fuse or shut off the breaker. or make it impossible for the furnace to operate. Of course, the moisture absorbed by the quartz in its initial state can be removed to some extent by opening the lid 5 and heating it with a heater at several hundred degrees Celsius for several hours, but this cannot be done completely. or,
We also tried a method of actively drying the quartz tape by raising the temperature of the heater 2 while exhausting the air inside the furnace with a pump through a pressurizing gas inlet (not shown) attached to the lid 5. However, with both methods, a certain amount of moisture remained and although the number of power cut-off accidents was reduced, it was not possible to completely eliminate power cut-off accidents. The reason why moisture cannot be completely expelled is that due to the good insulation properties of the quartz tape itself, the temperature does not reach the inner wall of the high-pressure vessel that the quartz tape is in contact with, and moisture remains in this area. It is possible to do so.

An object of the present invention is to provide a high-temperature pressure vessel that eliminates electrical leakage accidents caused by electrical terminals installed through the side wall of the vessel and improves the operating rate of the apparatus.

[Means for solving problems]

The present invention has a heater built into the container body, a heat insulating material made of quartz glass fiber interposed between the heater and the container body, and a group of electrical terminals installed through the side wall of the container body. A high-temperature pressure vessel characterized in that a collection reservoir is installed along the inner wall of the main body at a position above the electrical terminal group to collect water droplets that condense within the container body and descend along the inner surface of the side wall. It is.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram for explaining the present invention, in which a collection reservoir 8 for collecting water droplets is shaped like a droplet,
On the outside of the upper part, a male thread 8a is provided at the same pitch as the female thread 1a provided at the top of the inner wall of the main body 1 of the high-pressure vessel. Also, there is a hole 8b at the bottom.
is drilled, and a flange 9 is attached around the hole 8b.

Therefore, in the present invention, the male thread 8a of the collection reservoir 8 is engaged with the female thread 1a of the container body 1, and the collection reservoir 8 is installed along the inner wall of the upper space 7 of the container body 1.

When the high-pressure container is put into operation and the heater 2 is heated, water vapor is generated from the heat insulating material 3 and enters the upper space 7 through the hole 8b at the bottom of the recovery reservoir 8 as shown by the arrow. The water then contacts the low temperature inner wall of the lid 5 and the inner wall of the collection tank 8 and turns into water droplets, and when they reach a certain size, they descend along the inner wall as shown by the arrow until they reach the bottom, but they drop further due to the flange 9. Instead, it accumulates here. That is, it does not reach the inside of the furnace where the electrical terminal group 4 is present and electrically short-circuit them.

Next, the results of experiments using the present invention will be described below. Even if this invention is implemented, the insulation material 3
Since it is desirable that the sample ampoule contain as little moisture as possible, it was dehydrated before putting the sample ampoule into the furnace core, the heater 2 was energized without the lid 5 attached, and the sample was left at 800°C for 8 hours. After that, turn off the power, let it cool naturally, and when the temperature drops to 200℃, place the quartz ampoule containing the high vapor pressure material prepared in advance into the furnace core.
A collection reservoir 8 was installed and the lid 5 was fixed. Natural cooling
The reason for setting the temperature to 200℃ is to prevent moisture from re-absorbing from the air if the temperature is lower than 100℃.

Next, the air in the high-pressure container was exhausted through the gas inlet, and 9 atmospheres of inert gas was introduced in its place.
This gas pressure should be 30 atm at 800°C, which is reached in this experiment, and is intended to prevent the ampoule from exploding due to high pressure inside the quartz ampoule. After such preparation, the heater 2 was heated according to a normal program and heat treatment was performed at a predetermined temperature for several hours, but the power breaker did not trip at any temperature stage during the experiment. After finishing, collection tank 8
Approximately 2 c.c. of water droplets had accumulated in the tank. Same experiment 4
The procedure was repeated several times, but the progress and results were the same. Furthermore, the breaker did not shut off even in similar and identical experiments conducted in a state in which the heater 2 was not heated in advance, that is, in a state in which water was absorbed (in this case, the quartz ampoule was excluded). However, a little more than 4 c.c. of water was recovered in the recovery reservoir 8.

[Effect of idea]

As detailed above, according to the present invention, water droplets are prevented from adhering to the electrical terminal group, thereby preventing accidents such as power cut-off due to short-circuiting of power supply terminals, etc. This has the effect of improving the operating rate of the device.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing one embodiment of the present invention;
Figure a is a cross-sectional view of a conventional high-temperature and high-pressure furnace, Figure 2 b
is a temperature distribution diagram of the furnace. 1... Container body, 2... Heater, 3... Insulating material, 4... Electrical terminal group, 5... Lid, 6... Bolt, 7... Space, 8... Recovery reservoir, 9... Flange.

Claims (1)

[Scope of utility model registration request] A high-temperature pressure vessel that has a heater built into the container body, a heat insulating material made of quartz glass fiber interposed between the heater and the container body, and a group of electrical terminals installed through the side wall of the container body. A high-temperature pressure vessel according to the present invention, characterized in that a collection reservoir for collecting water droplets that condense within the vessel body and fall down along the inner surface of the side wall is installed along the inner wall of the body at a position above the electrical terminal group.