How to Choose a Tubular Furnace?

1. According to the highest temperature required for the experiment, select a heating furnace with a suitable temperature range

A. When choosing the working temperature, please pay attention to the highest temperature that the instrument can maintain (<1 hour) and the temperature at which the instrument can work continuously (safe, continuous use temperature)

B. The heating element used by the instrument limits the maximum working temperature of the heating furnace

(1) 250 ~ 1250 ℃ using resistance wire heating element, the maximum heating temperature is 1200 ℃, long-term use of 1100 ℃ or infrared lamp heating element, using K-type thermocouple for temperature measurement (can also be replaced with S thermocouple if customer needs)

(2) 1300 ~ 1600 ℃ using silicon carbide heating element, using S-type thermocouple temperature measurement

(3) 1600 ~ 1800 ℃ using MoSi2 heating element (forbid to heat under 800 ℃ for a long time), using B type thermocouple for temperature measurement

2. Select the appropriate crucible and furnace tube diameter according to the sample size, and select the heating furnace with appropriate volume. (It is not recommended to directly put the sample into the furnace tube without crucible loading)

A. Crucible selection

· A. Quartz crucible: use quartz tube ≤1200℃, when the heat treatment temperature exceeds 600℃, please do not use alumina crucible

· B. Alumina crucible: use corundum tube ≤1800℃, when heat treatment temperature exceeds 900℃, please do not use mullite crucible

· C. Graphite crucible: ≤ 2300℃

1. Need to heat-treat the powder at 900℃, select the quartz crucible to load the sample

2. The alloy needs to be melted at 1600 ℃, select alumina crucible

B. Selection of pipe diameter

After selecting the crucible, select the appropriate furnace tube diameter according to the volume of the crucible after the sample is loaded (generally, the furnace will be equipped with a heating furnace tube as a standard)

· A. Quartz tube  ≤1200℃  (Maximum 1000℃ under vacuum environment)

For example all kinds of samples

· B. Corundum tube  ≤1800℃  (Corundum tube is not recommended for use in a vacuum environment)

3. According to the experimental requirements, choose a single-temperature zone tube heating furnace and a multi-temperature zone tube heating furnace. There will be multiple thermocouples in the multi-temperature zone compared to the single-temperature zone. The n-zone heating furnace has a constant temperature zone ratio (n-1 ) The temperature zone of the heating furnace in the temperature zone is longer, and some instruments become larger in size.