A manual critical point dryer

Abstract

The utility model discloses a manual critical point drying appearance belongs to sample preparation equipment technical field. The drying appearance includes liquid carbon dioxide steel bottle, T type filter and the main pipeline system of connecting through high pressure hose. The main pipeline system is equipped with three parallel pipe lines, and every pipe line has ball valve and handle needle valve with scale in series, is respectively used for realizing the quick cooling of sample cavity, slow liquid filling and quick liquid filling. Sample cavity is equipped with pressure and temperature display controller, and its internal structure is designed to make liquid carbon dioxide entrance and chamber center axis 30~45 degree angle, to form vortex stirring, and is equipped with magnetic stirring device, promotes the mixture. Condensing separator separates carbon dioxide and waste liquid through electric heating, and waste liquid is discharged into waste liquid bottle. The utility model improves the flow stability and instrument life through valve combination, through the unique cooling, mixing and slow pressure relief mode, effectively prevents sample damage, improves the reliability and effect of drying process.

Description

Technical Field

[0001] This utility model relates to the field of sample preparation equipment technology, and in particular to a manual critical point dryer for sample pretreatment in electron microscopes. Background Technology

[0002] Critical point dryers are crucial equipment for scanning electron microscopy (SEM) sample preparation, used to remove solvents from samples without damaging their microstructure. Existing equipment often suffers from problems such as unstable pressure control, slow cooling rates, uneven mixing, and sample damage due to excessively rapid pressure release. Furthermore, traditional needle valve adjustments have poor repeatability and short lifespan, affecting experimental efficiency and the consistency of results. Utility Model Content

[0003] The purpose of this invention is to provide a manual critical point dryer that is easy to operate, has precise pressure control, provides uniform mixing, cools quickly, and has a long service life. To achieve the above objective, this invention adopts the following technical solution: A manual critical point dryer includes a liquid carbon dioxide cylinder 1 with a siphon tube, a sample chamber 8, and connecting pipes. The liquid carbon dioxide cylinder 1 is connected to an intake control unit consisting of three parallel pipes via a T-type filter 2. Each of the three parallel pipes is connected in series with a ball valve 3 and a graduated needle valve 4. The three pipes are used for rapid depressurization and cooling of the sample chamber 8, slow filling with liquid carbon dioxide, and rapid filling with liquid carbon dioxide, respectively. The sample chamber 8 is connected to a pressure display controller 6 and a temperature display controller 7. The outlet pipe of the sample chamber 8 is connected to a condenser separator 9 via the ball valve 3 and the graduated needle valve 4. The lower outlet of the condenser separator 9 is connected to a waste liquid bottle 10, and a gas discharge port is provided at the top.

[0004] Furthermore, the inner cavity of the sample chamber 8 is a hollow cylinder, with a liquid carbon dioxide inlet pipe extending into the chamber. The inlet's orientation forms a 30-45° angle with the central axis of the cylinder, creating a vortex in the flowing liquid carbon dioxide. Furthermore, a magnetic stirring device is installed at the bottom of the sample chamber 8. Furthermore, the condenser separator 9 is equipped with an electric heating device, with its operating temperature controlled between 35-55°C. Furthermore, a pressure relief pipe is provided at the top of the sample chamber 8, with a ball valve 3 and a graduated needle valve 4 connected in series on this pipe for slowly depressurizing the supercritical carbon dioxide into a gaseous state. Furthermore, the handle of the graduated needle valve 4 has a graduated dial that can be fixed in position. The innovative points of this utility model include:

[0005] 1. The combination of a high-pressure ball valve and a needle valve with a graduated handle ensures stable flow, high repeatability, and extends the service life of the needle valve;

[0006] 2. The sample chamber uses carbon dioxide adiabatic refrigeration, which provides rapid cooling and is easy to maintain;

[0007] 3. The sample chamber inlet is designed at an inclined angle to create vortex stirring and promote the mixing of solvent and carbon dioxide;

[0008] 4. The sample chamber has a built-in magnetic stirring function to further enhance the mixing effect;

[0009] 5. The condenser separator achieves efficient separation of carbon dioxide and waste liquid through electric heating;

[0010] 6. Supercritical carbon dioxide is slowly depressurized through ball valves and needle valves to prevent the sample from being damaged due to increased surface tension. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of this utility model. In the figure: 1-liquid carbon dioxide cylinder, 2-T-type filter, 3-ball valve, 4-needle valve with graduated handle, 5-one-way valve, 6-pressure display controller, 7-temperature display controller, 8-sample chamber, 9-condenser separator, 10-waste bottle. Detailed Implementation

[0012] The present invention will be further described below with reference to the accompanying drawings: In use, the valve of the liquid carbon dioxide cylinder 1 is opened, and the liquid carbon dioxide enters the dryer through the T-type filter 2. Rapid cooling, slow filling, and rapid filling functions are achieved through three pipelines. The pressure and temperature inside the sample chamber 8 are monitored in real time by the pressure display controller 6 and the temperature display controller 7. The inner cavity of the sample chamber 8 is a hollow cylinder, with its liquid carbon dioxide inlet pipe extending into the chamber. The orientation of this inlet forms an angle of 30-45° with the central axis of the cylinder, causing the flowing liquid carbon dioxide to generate a vortex. A magnetic stirring device is installed at the bottom of the sample chamber 8. The condenser separator 9 is equipped with an electric heating device, whose operating temperature is controlled between 35-55℃. A pressure relief pipe is provided at the top of the sample chamber 8, with a ball valve 3 and a graduated needle valve 4 connected in series on this pipe for slowly depressurizing the supercritical carbon dioxide into a gaseous state. The handle of the graduated needle valve 4 has a graduated dial that can be fixed in position. The treated mixture enters the condenser separator 9, the waste liquid is collected in the waste liquid bottle 10, and gaseous carbon dioxide is discharged. Supercritical carbon dioxide is discharged through a slow pressure relief method to avoid sample damage. This invention has a simple structure and is easy to operate, making it suitable for critical point drying of small batches of samples in the laboratory. It has high practical value and promising prospects for wider application.

Claims

1. A manual critical point dryer, comprising a liquid carbon dioxide cylinder (1), a sample chamber (8), and connecting pipes, characterized in that: The liquid carbon dioxide cylinder (1) is connected to the air intake control unit consisting of three parallel pipes through a T-type filter (2). Each of the three parallel pipes is connected in series with a ball valve (3) and a needle valve (4) with a graduated handle. The three pipes are used to rapidly depressurize and cool the sample chamber (8), slowly fill it with liquid carbon dioxide, and rapidly fill it with liquid carbon dioxide, respectively. The sample chamber (8) is connected to a pressure display controller (6) and a temperature display controller (7). The outlet pipe of the sample chamber (8) is connected to a condenser (9) through the ball valve (3) and the needle valve (4) with a graduated handle. The lower outlet of the condenser (9) is connected to a waste liquid bottle (10), and the top is provided with a gas discharge port.

2. The manual critical point dryer according to claim 1, characterized in that: The inner cavity of the sample chamber (8) is a hollow cylinder, and its liquid carbon dioxide inlet pipe extends into the chamber. The orientation of the inlet forms an angle of 30~45° with the central axis of the chamber cylinder, so that the flowing liquid carbon dioxide generates a vortex.

3. The manual critical point dryer according to claim 1 or 2, characterized in that: A magnetic stirring device is provided at the bottom of the sample chamber (8).

4. The manual critical point dryer according to claim 1, characterized in that: The condenser separator (9) is equipped with an electric heating device, and its operating temperature is controlled between 35 and 55°C.

5. The manual critical point dryer according to claim 1, characterized in that: The top of the sample chamber (8) is provided with a pressure relief pipe, on which a ball valve (3) and a needle valve (4) with a graduated handle are connected in series to slowly depressurize supercritical carbon dioxide into a gaseous state for discharge.

6. The manual critical point dryer according to claim 1, characterized in that: The handle of the needle valve (4) with graduated handle has a graduated dial that can be fixed in position.

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