Gas filled tube furnace

A gas filled tube furnace is a type of furnace that can heat materials by introducing specific gases. It is widely used in enterprise laboratories, university laboratories, and other scenarios. The following provides a detailed introduction from multiple dimensions:

1. Working principle
A tube furnace with gas flow is designed to meet the process requirements of material preparation and heat treatment by introducing protective gases (such as nitrogen, argon) or reactive gases into the furnace tubes, combined with a heating system, to achieve the desired temperature of the material in a specific atmosphere environment. The energy conversion process is as follows:
Conversion of electrical energy into thermal energy: Resistance heating elements (such as nickel chromium alloys, silicon carbon rods, silicon molybdenum rods) generate heat after being energized.
Heat transfer: The heating element transfers heat to the furnace tube through thermal radiation and conduction, and the furnace tube then transfers the heat to the material inside the tube.
Gas action: The introduced gas serves to protect, participate in reactions, or regulate the atmosphere. For example, protective gases can prevent sample oxidation, and reactive gases can participate in chemical synthesis.

2. Core structure
Furnace tube:
Material: Choose according to the temperature and atmosphere requirements, such as quartz tube (≤ 1200 ℃), corundum tube (≤ 1700 ℃), stainless steel tube, etc.
Function: As a space for material placement and reaction, it needs to have good high temperature resistance and chemical stability.
Heating element:
Type: Resistance wire (such as nickel chromium alloy), silicon carbon rod, silicon molybdenum rod, etc.
Selection criteria: Select based on temperature range, for example:
250-1250 ℃: Fe Cr Al or NiCr Al alloy heating element.
1300~1600 ℃: SiC heating element.
1600~1800 ℃: MoSi ₂ heating element.
Insulation layer:
Material: Insulation materials such as refractory bricks and ceramic fibers.
Function: Reduce heat loss and improve energy utilization efficiency.
Temperature control system:
Composition: Thermocouple (real-time temperature monitoring), temperature control instrument (comparing measured values with set values), power regulation device (adjusting heating power through PID algorithm).
Accuracy: The high-precision temperature control system ensures temperature stability, with a temperature control accuracy of ± 1 ℃.
Gas control system:
Composition: gas source, gas pipeline, flow meter, valve, etc.
Function: Accurately control the type and flow rate of gas entering the furnace tube, supporting the mixed use of multiple gases (such as nitrogen, argon, hydrogen, oxygen).

3. Types and classifications
Classified by structure:
Single tube/double tube: The single tube furnace is suitable for simple experiments, while the double tube furnace can simultaneously process different samples or atmospheres.
Horizontal/Vertical: Horizontal furnaces have a large footprint and are suitable for long-term heating; Vertical furnaces have a small footprint and are suitable for rapid heating or quenching processes.
Rotating/openable type: The rotating tube furnace is suitable for occasions with high requirements for powder processing or coating uniformity; The openable furnace facilitates sample loading and unloading.
Classified by temperature zone:
Single temperature zone/multi temperature zone: The multi temperature zone furnace has multiple independently controlled constant temperature zones, suitable for experiments that require temperature gradients or long-term heating.
Classified by atmosphere control:
Vacuum operation: Some tube furnaces can be evacuated for oxygen free treatment, suitable for experiments that are sensitive to oxygen.
Two stage gas design: By controlling different gas flow rates and compositions through two independent gas channels, different atmosphere environments can be formed inside the furnace. For example, one section is filled with protective gas to prevent sample oxidation, while the other section is filled with reactive gas for reduction reaction or chemical synthesis.

4. Application Fields
Materials Science:
Nanomaterial synthesis: Preparation of high-purity metal nanoparticles by controlling the atmosphere and temperature.
Ceramic sintering: promoting the densification of ceramic materials in a specific atmosphere.
Chemical research:
Catalyst preparation: Prepare efficient catalysts in a reducing atmosphere.
Gas deposition: Using reactive gases to deposit thin films on the surface of materials.
Metallurgical Engineering:
Metal heat treatment: Annealing, quenching, and other treatments of metals in an inert or reducing atmosphere.
Powder metallurgy: By controlling the atmosphere to prevent powder oxidation and improve material properties.
Semiconductor industry:
Wafer processing: Performing processes such as oxidation and diffusion on wafers in an oxidizing or reducing atmosphere.

5. Purchase Guide
Clear usage requirements:
Application scenarios: material heat treatment, metal annealing, powder processing, coating uniformity, etc.
Temperature range: Select appropriate heating elements and furnace tube materials according to experimental requirements.
Focus on core parameters:
Heating zone length: It should be long enough to cover the entire sample and ensure uniform heating.
Constant temperature zone: Choose a heating furnace with a constant temperature band longer than the sample to ensure temperature stability.
Atmosphere control: Choose a tube furnace that supports vacuum, inert gas protection, or reaction gas introduction according to experimental requirements.
Considering security performance:
Safety protection functions: over temperature alarm, leakage protection, emergency shutdown, etc.
Explosion proof and ventilation design: For experiments using flammable and explosive gases, it is necessary to choose a tube furnace with explosion-proof design and ensure good ventilation in the laboratory.
Evaluate equipment size and layout:
Size selection: Choose the appropriate size of the tube furnace based on the space size of the laboratory or production workshop.
Layout method: Consider the convenience of device operation and maintenance space.
Value after-sales service:
Supplier reputation: Choose manufacturers with good brand reputation and word-of-mouth.
After sales service quality: Ensure timely technical support and maintenance services during use.