When choosing a large diameter pilot tube furnace, it is necessary to consider experimental requirements, sample characteristics, and process conditions, and conduct a comprehensive evaluation from five core dimensions: temperature range, furnace tube size, temperature zone design, functional expansion, safety, and stability. Let's take a detailed look below!

Large diameter quartz tube pilot type tube furnace (click on the picture to view product details)

1. Temperature range: Match experimental requirements, clarify maximum temperature and continuous operating temperature
Maximum temperature: Select the type of heating element based on the maximum processing temperature required for the experimental material
≤ 1200 ℃: Fe Cr Al or Ni Cr Al alloy heating elements (such as resistance wires) are selected, which have lower costs and are suitable for routine experiments such as metal heat treatment and ceramic sintering.
1300-1600 ℃: Using silicon carbon rod (SiC) heating elements, it has good high temperature resistance and is suitable for high-temperature alloy melting, carbon material graphitization and other scenarios.
≥ 1600 ℃: Silicon molybdenum rod (MoSi ₂) heating element is required, supporting high-end experiments such as nano material synthesis and semiconductor wafer annealing, but attention should be paid to avoiding long-term low-temperature operation (≤ 800 ℃) to prevent component oxidation.
Continuous operating temperature: Ensure that the equipment can operate stably for a long time at the target temperature, avoiding damage to heating elements or furnace tubes due to overheating. For example, if the experiment requires continuous processing of the sample at 1000 ℃, a tube furnace with a continuous working temperature of ≥ 1000 ℃ should be selected.

2. Furnace tube size: adapted to sample specifications, taking into account operational convenience
Pipe diameter selection:
Advantages of large pipe diameter: Pilot type tube furnaces usually use pipe diameters of over 150mm, which can accommodate multiple samples or large samples (such as powder tablets and film substrates), improving experimental efficiency.
Material matching: Select furnace tube material based on temperature range:
Quartz tube: suitable for experiments at ≤ 1200 ℃, with good transparency and easy optical monitoring (such as graphene growth).
Aluminum oxide tube (corundum tube): Temperature resistance ≤ 1700 ℃, strong chemical stability, suitable for experiments in corrosive atmospheres.
Stainless steel alloy tube: Excellent pressure resistance and supports high-pressure gas environments (such as CVD deposition).
Furnace tube length: It needs to cover the total length of the sample and reserve operating space to ensure uniform heating. For example, when processing samples with a length of 200mm, a tube furnace with a constant temperature zone length of ≥ 250mm should be selected.

3. Temperature zone design: Choose single or multiple temperature zones according to process requirements
Single temperature zone tube furnace:
Simple structure: Low cost, suitable for experiments under a single temperature condition (such as powder sintering).
Limitations: Unable to achieve temperature gradient control, which may affect sample uniformity.
Multi zone tube furnace:
Independent temperature control: Multiple constant temperature zones (such as dual temperature zone, triple temperature zone) can be set to achieve temperature gradient or segmented heating, suitable for complex processes such as diffusion experiments and material synthesis.
Constant temperature zone length: The total length of the constant temperature zone of a multi temperature zone furnace is usually greater than that of a single temperature zone furnace, but attention should be paid to the temperature difference between adjacent temperature zones (generally ≤ 300 ℃) to avoid thermal stress damage.

4. Function extension: meet special experimental needs
Vacuum and atmosphere control:
Vacuum system: The mechanical pump can achieve a vacuum degree of 100Pa, and the molecular pump can further reduce it to 10 ⁻⁴ Pa, suitable for scenarios such as semiconductor material preparation and high-temperature corrosion research.
Gas inlet: Equipped with an inlet and precision needle valve, it can introduce inert gases (such as Ar, N ₂) or reactive gases (such as H ₂, CH ₄), supporting CVD deposition, redox experiments, etc.
Rotation function:
Rotating tube furnace: The furnace tube can rotate uniformly to improve the uniformity of heat treatment of powder samples or achieve coating effects (such as metal coating deposition).
Rapid Heat Treatment (RTP):
High speed temperature rise and fall: By using sliding sample heating technology, second level temperature rise and fall can be achieved (such as from room temperature to 1000 ℃ in only 15-30 seconds), suitable for experiments such as rapid annealing and thin film crystallization.

5. Safety and Stability: Ensuring Experimental Safety and Data Reliability
Safety device:
Overtemperature protection: When the temperature exceeds the set value, it automatically shuts off and alarms to prevent equipment damage.
Vacuum monitoring: Real time display of the vacuum level inside the furnace to avoid experimental failure caused by gas leakage.
Pressure protection: For high-pressure furnaces, equipped with pressure relief valves to prevent furnace tube bursting.
Temperature control accuracy:
PID control: Through fuzzy PID algorithm and self-tuning adjustment, precise temperature control (within ± 1 ℃) is achieved to ensure experimental repeatability.
Program heating: Supports 30 programmable temperature control curves to meet complex process requirements such as step-by-step annealing and gradient heating.
Furnace material:
High purity alumina ceramic fiber: with excellent high temperature resistance and thermal insulation performance, it can reduce heat loss and lower energy consumption.
Stainless steel shell: sturdy structure, corrosion-resistant, suitable for industrial grade pilot experiments.

6. Brand and after-sales service: reduce long-term usage costs
Brand selection: Priority should be given to brands with industry reputation, as their product quality and after-sales service are more guaranteed.
Warranty period: Pay attention to the equipment warranty period (usually 1 year) and whether it includes replacement services for consumables such as furnace tubes and O-rings.
Technical support: Choose suppliers who provide technical training, remote fault diagnosis, and rapid response services to reduce equipment downtime.

Large diameter variable diameter tube rotating inclined tube furnace (click on the picture to view product details)

In general, when choosing a large diameter pilot tube furnace, attention should be paid to the above aspects. You can consult relevant technical personnel before choosing, so as to customize a larger diameter pilot tube furnace that is more suitable for your own experiment or production!Click to learn more tube furnaces! Or click on online customer service to learn more about product information!