Working principle of experimental high-temperature tube sintering furnace

Experimental high-temperature tube sintering furnace is a device used for high-temperature experiments such as material sintering and heat treatment. Its working principle is mainly based on electric heating effect and atmosphere control technology. The following is a detailed explanation of its working principle:

1. Heating principle
Electric heating effect:
High temperature tube sintering furnaces usually use resistance wires (such as nickel chromium alloy wires), silicon carbon rods, or silicon molybdenum rods as heating elements.
When current passes through the heating element, due to the presence of resistance, electrical energy is converted into thermal energy, causing the temperature of the heating element to rise.
The heat generated by the heating element is transferred to the sample inside the furnace tube through radiation, convection, and conduction, reaching the temperature required for sintering or heat treatment.
Temperature control:
The furnace body is usually equipped with a precise temperature control system, including temperature sensors and temperature control instruments.
The temperature sensor monitors the temperature inside the furnace in real time and transmits the temperature signal to the temperature control instrument.
The temperature control instrument adjusts the power of the heating element to control the temperature inside the furnace based on the set temperature curve and temperature deviation, achieving precise temperature control.

2. Principles of Atmosphere Control
Atmosphere selection:
High temperature tube sintering furnaces can be tested under different atmospheric conditions, such as air, vacuum, inert gases (such as nitrogen, argon), or reducing gases (such as hydrogen).
The choice of atmosphere depends on the experimental requirements and material properties.
Atmosphere control:
The furnace body is usually equipped with a gas supply system and a vacuum system to control the atmosphere inside the furnace.
The gas supply system introduces the required gas into the furnace through gas pipelines and adjusts the gas flow rate through a flow controller.
The vacuum system uses a vacuum pump to evacuate the furnace to a vacuum state, in order to meet the requirements of certain experiments for low-pressure environments.
During the experiment, adjust the gas flow rate, pressure, and other parameters according to the experimental requirements to maintain the stability of the furnace atmosphere.

3. Furnace structure and heat transfer
Furnace structure:
The body of a high-temperature tube sintering furnace is usually composed of a furnace shell, furnace chamber, furnace tubes, and heating elements.
The furnace shell is made of high-quality steel plates and insulation materials, with good sealing and insulation performance.
The furnace lining is made of high-temperature resistant ceramic fiber material, which is used to reduce heat loss and improve heating efficiency.
The furnace tube is made of materials that are resistant to high temperatures and corrosion, such as quartz glass, stainless steel, or corundum, and is used to place samples and isolate the external environment.
Heat transfer method:
The heat generated by the heating element is mainly transferred to the sample inside the furnace tube through radiation.
At the same time, the hot air inside the furnace will also transfer heat to the sample through convection.
The contact between the furnace tube and the sample also transfers heat through conduction, but this method is usually not the main heat transfer method in tube sintering furnaces.

4. Working process
Sample preparation:
Prepare samples according to experimental requirements and place them on suitable containers or supports.
Furnace loading:
Open the furnace door, place the container or support containing the sample into the furnace tube, and close the furnace door.
Vacuumize or introduce gas:
Select vacuum pumping or gas injection according to experimental requirements, and adjust parameters such as gas flow rate and pressure.
Heating and insulation:
Start the heating system and raise the temperature inside the furnace to the desired temperature according to the set temperature curve.
During the insulation stage, maintain a stable temperature inside the furnace to allow the sample to fully sinter or undergo heat treatment.
Cooling and baking:
After the experiment, turn off the heating system and let the temperature inside the furnace naturally decrease or use rapid cooling to cool down.
When the temperature inside the furnace drops to a safe range, open the furnace door and take out the sample.