Precautions for selection of large box type muffle furnace

As a commonly used heat treatment electric furnace in industry, the large box type muffle furnace is favored by major manufacturers for its low price and high processing efficiency. It is commonly used for various processes such as metal parts annealing, powder sintering, brazing, etc. So, what aspects should be paid attention to when choosing a large box type muffle furnace? Let’s take a look below!

Customized industrial high-temperature box type electric furnace (click on the picture to view product details)

1. Clarify application requirements
Process type
High temperature sintering/heat treatment: Attention should be paid to the maximum temperature, heating rate, and insulation performance.
Ash content determination/volatile matter analysis: Must comply with ASTM, ISO and other standards, with high temperature uniformity requirements.
Atmosphere protection experiment: It is necessary to support the introduction of inert/reducing gases and equip with airtight design.

Sample characteristics
Size and weight: Select the furnace size based on the sample volume (such as 500 × 500 × 600mm or more), and confirm the load-bearing capacity (such as ≥ 50kg).
Corrosivity: If the sample contains corrosive substances, corrosion-resistant furnace materials (such as corundum mullite composite furnace) should be selected.

2. Key components and configurations
Furnace material
Aluminum oxide fiber: lightweight, good insulation, but poor impact resistance, suitable for ≤ 1300 ℃.
Mullite fiber: high temperature resistance (1600 ℃+), good thermal shock resistance, suitable for frequent start stop.
Silicon carbide/corundum: high strength, corrosion resistance, but high cost, suitable for special processes.

heating element
Silicon molybdenum rod (MoSi ₂): 1300 ℃ -1800 ℃, strong oxidation resistance, but it is necessary to avoid low-temperature oxidation at 400-700 ℃.
Silicon carbide rod (SiC): 1000 ℃ -1500 ℃, heats up quickly, but is prone to aging and needs to be replaced regularly.
Kanthal resistance wire: ≤ 1200 ℃, low cost, but short lifespan.

Sealing and atmosphere control
Airtightness: The furnace door is sealed with metal or silicone O-ring to ensure a leakage rate of ≤ 1 × 10 ⁻³ Pa · m ³/s.
Gas path design: Supports multi-channel gas switching and is equipped with a mass flow meter (MFC) for precise flow control.
Vacuum function: optional mechanical pump+diffusion pump, with a vacuum degree of 10 ⁻ Pa level, suitable for vacuum sintering.

3. Safety and operational design
Safety protection
Overtemperature alarm: Automatic power-off when the temperature exceeds the set value ± 10 ℃.
Broken thermocouple protection: Stop heating when the thermocouple breaks to prevent “flying temperature”.
Overcurrent/overvoltage protection: to prevent accidents caused by electrical faults.
Explosion proof design: Equipped with explosion-proof valves or pressure relief devices for flammable atmospheres such as hydrogen.

Convenience of operation
Temperature control system: supports PID self-tuning and multi-stage program temperature control (such as heating insulation cooling curve).
Human computer interface: touch screen or PLC control, supports switching between Chinese and English, data recording and export.
Remote monitoring: Optional IoT module for remote operation and fault diagnosis on mobile phones/computers.

4. Suppliers and after-sales service
Supplier Qualification
Assess the manufacturer’s research and development experience in the field of high-temperature furnaces (e.g. ≥ 10 years), and prioritize selecting industry-leading brands.

after-sale service
Response time: Provide 7 × 24-hour technical support, fault response ≤ 24 hours, spare parts supply ≤ 72 hours.
Training services: Provide on-site operation training and maintenance guidance to ensure users are proficient in using it.

5. Summary of Selection Process
Requirement confirmation: Clarify core requirements such as process, sample, temperature, atmosphere, etc.
Parameter comparison: Select 3-5 suppliers based on the key indicators in the table.
Field visit: Visit the manufacturer’s production workshop and test the performance of the prototype.
Business negotiation: Confirm price, delivery time, and warranty terms.
Acceptance and Training: Performance acceptance will be conducted after the equipment arrives, and operational training will be arranged.

Customized industrial box type muffle furnace (click on the picture to view product details)

Through the above steps, it can be ensured that the selected large box type muffle furnace meets production needs while considering safety, economy, and long-term stability. You can communicate with relevant technical personnel about the parameters you need before choosing, so that you can purchase a box type muffle furnace that suits your production needs!Click to learn more muffle furnaces! Or click on online customer service to learn more about product information!