Open type vacuum tube furnace is a device used for high-temperature heating treatment, especially suitable for experiments and production processes that require vacuum or specific atmospheres. Its working principle mainly includes the following aspects:

1、 Heating principle

The core of an open type vacuum tube furnace is the heating element, and common heating elements include silicon molybdenum rods, silicon carbide rods, and molybdenum wires. These heating elements generate high-temperature heat energy through resistance heating. When the current passes through the heating element, the element generates heat due to resistance, which is then transferred to the furnace tube and sample.

2、 Vacuum system

The vacuum system is an important component of an open vacuum tube furnace, usually composed of a vacuum pump, vacuum valve, and vacuum pipeline. The working process is as follows:

Vacuum pumping: Start the vacuum pump and extract the gas from the furnace tube through the vacuum pipeline and valve, creating a high vacuum environment. In a high vacuum environment, the number of gas molecules is significantly reduced, reducing the oxidation and contamination of the sample, making it suitable for oxygen sensitive materials and reactions.

Maintain vacuum: After reaching the set vacuum degree, close the vacuum valve and maintain the vacuum state inside the furnace tube. Throughout the heating process, the vacuum system will continue to operate to maintain a stable vacuum environment.

3、 Atmosphere control

In some applications, heating treatment is required in specific atmospheres such as nitrogen, argon, hydrogen, etc. The open type vacuum tube furnace achieves this through an atmosphere control system:

Gas introduction: After vacuuming, the required gas is introduced into the furnace tube through an atmosphere control system. The gas flow rate and pressure are regulated through a gas flow controller and regulating valve to ensure the stability and consistency of the atmosphere.

Atmosphere maintenance: Throughout the heating process, the atmosphere control system continuously supplies gas to maintain the gas environment inside the furnace tube unchanged, in order to meet different experimental and production needs.

4、 Temperature control

The temperature control system is a crucial part of an open vacuum tube furnace, typically consisting of a temperature controller, thermocouple, and temperature sensor:

Temperature measurement: Thermocouples or temperature sensors are installed inside the furnace tube or near the sample to monitor the temperature in real time and transmit the temperature signal to the temperature controller.

Temperature regulation: The temperature controller controls the current of the heating element through PID adjustment algorithm based on the set temperature program and real-time measurement temperature, accurately adjusts the heating power, and ensures that the temperature remains stable near the set value.

5、 Sample processing

The samples are placed on the sample rack inside the furnace tube, and the sample loading and unloading are very convenient through an open design. During the heating process, the sample is treated at high temperature and in a specific atmosphere or vacuum environment to achieve experimental or production purposes.

6、 Cooling process

After the heating process is completed, cooling is usually required:

Natural cooling: Turn off the heating element and allow the furnace tube and sample to cool naturally, suitable for samples that do not have strict requirements for cooling rate.

Rapid cooling: When rapid cooling is required, the cooling process can be accelerated by introducing cooling gas (such as nitrogen) or a water-cooling system to protect sample characteristics or facilitate rapid turnover.

7、 Conclusion

The open type vacuum tube furnace achieves sample processing under high temperature, vacuum or specific atmosphere conditions through a precise heating system, stable vacuum and atmosphere control, and temperature adjustment. This type of equipment is widely used in materials science, chemical synthesis, physical research, metallurgy and other fields, and can meet various complex experimental and production needs.