JPS636682Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a pressure vessel of a critical point drying device used for preparing a sample for a scanning electron microscope.

In the critical point drying device, a sample that has been dehydrated, fixed, and replaced with an appropriate reagent is stored in a pressure vessel, and a mediating solvent such as liquid carbonic acid or liquid Freon is injected into the container, and the mediating solvent is separated from the liquid phase and gas. This is a device that dries the sample by heating it so that it changes to a gaseous phase through a mixed state. In such a device, at the stage when liquefied gas such as liquid carbonate is introduced into the pressure vessel,
It is extremely important to check whether the amount has reached the predetermined amount before proceeding to the next step.
In particular, if the operation is continued without sufficient liquefied gas, the drying process may fail and valuable samples may be wasted.

For this reason, in conventional equipment, a window made of hard glass or the like is provided on the top of the container so that the inside can be seen through this window, but when carbon dioxide gas is used as the mediating solvent, the inside becomes over 100 atmospheres. For,
The window has to be made very small. Therefore, it is very difficult to see inside, and since the height of the liquid level must be checked from above, accurate observations cannot be made without considerable training. Therefore, this confirmation is often neglected, and the liquid level is predicted only based on the indication from the pressure gauge connected to the container or its piping, and the process proceeds to the next step, but this often results in drying failure.

The present invention aims to eliminate such drawbacks and will be described below with reference to the drawings.

In the embodiment shown in FIG. 1, reference numeral 1 denotes a pressure vessel made of a strong material such as stainless steel, to which an introduction pipe 2 for a medium solvent (liquefied gas) and an exhaust pipe 3 for the vaporized gas of the solvent are connected. Reference numeral 4 denotes a lid, which is removably provided at the top of the container, and the sample is taken in and taken out by opening this lid. A transparent window 5 made of hard glass or the like is attached to the front surface of the container 1 so as to maintain airtightness so that the inner surface is exposed inside the container. It is convenient to provide this window with a scale suitable for indicating the position in the vertical direction. With this structure, when the solvent (liquefied gas) 6 is injected, the liquid level can be observed from the right angle through the window 5, making it extremely easy to confirm its position, and the window itself can be used as a liquid level gauge. This also serves as an extremely accurate confirmation of the liquid level. Particularly, it is very convenient to have scale lines engraved on the window.

FIG. 2 shows another embodiment in which a lid 4 is disposed on the front surface and a window 5 is attached to this lid, and its operation and effect are exactly the same as in FIG. 1.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing one embodiment of the present invention, respectively. 1: Pressure vessel, 2: Solvent introduction pipe, 3: Solvent vaporized gas discharge pipe, 4: Lid, 5: Window, 6: Solvent.

Claims (1)

[Scope of utility model registration request] A sample that has been dehydrated, fixed, and replaced by a reagent is stored in a pressure vessel, a mediating solvent such as liquid carbonic acid or liquid Freon is injected, and the mediating solvent is heated to change the liquid phase to a mixed state of liquid and gas phases. A pressure vessel of an apparatus for drying the sample by transferring it to a gas phase through a process, and having a transparent window on the front side for observing the inside, and a scale on the window to indicate the position in the vertical direction. Pressure vessel of critical point drying equipment.