A rotary tube furnace is a type of experimental and production equipment used for heat treatment of powdered and granular materials under specific atmosphere conditions. It is widely used in industries such as activated carbon, metallurgy, glass, lithium battery materials, rare earth nanomaterials, and abrasives. Its core design ensures uniform heating of materials through the rotation of the furnace tube. Combined with precise temperature control and atmosphere regulation, it meets the requirements of sintering, roasting, and heat treatment processes. Depending on the degree of automation, rotary tube furnaces can be divided into conventional rotary tube furnaces and automatic loading and unloading rotary tube furnaces. The latter integrates a continuous loading and unloading system to further improve production efficiency.

Working Principle of a Rotary Tube Furnace

Heating Principle: Embedded alloy heating wires or other heating elements heat the material within the furnace through radiation and conduction, reaching temperatures exceeding 1200°C. The temperature control system utilizes multi-stage programmable PID intelligent control for precise temperature regulation and automatic operation.

Rotation Function: The furnace tube rotates via a gear transmission, and the speed is adjustable via a frequency converter, controlling the material’s residence time in the high-temperature zone to ensure uniform heating and sufficient reaction. Conventional equipment requires manual loading and unloading, while automatic loading and unloading models utilize a material bucket and conveyor mechanism for continuous loading and unloading.

Atmosphere Control: Double-ring sealing flanges on both ends of the furnace tube allow connection to a vacuum system or inert gas pipelines, creating atmospheres such as vacuum, nitrogen, and argon to meet specific material processing requirements.

Structural Components

Furnace: Double-layered, inner-liner construction with an air gap for insulation. The outer layer is constructed of carbon steel or stainless steel, while the inner layer is lined with alumina fiber, providing both high-temperature resistance and thermal insulation.

Drive System: Comprised of motors, gears, and rollers, it drives the furnace tubes for smooth rotation. Some models support forward and reverse rotation.

Temperature Control System: Consisting of thermocouples, temperature controllers, and heating elements, it provides closed-loop control, achieving a temperature fluctuation accuracy of ±1°C.

Technical Features of Rotary Tube Furnaces

Performance Advantages

Efficient and Energy-Saving: Lightweight and fast heating rates, the furnace chamber utilizes polycrystalline mullite fiber, saving up to 50% energy and maintaining a furnace surface temperature below 50°C (automatic fans provide cooling at high temperatures).

Safe and Reliable: Equipped with over-temperature protection, leakage protection, and automatic power-off upon furnace opening, flange sealing technology prevents gas leaks, ensuring high operational safety.

Convenient Operation: The quick-connect flange design simplifies gas line installation, requiring only clamps for securement. Select models feature a tiltable or reversible furnace body for convenient material handling and furnace tube maintenance.

Features:

1. Lightweight, fast heating, energy-saving, time-saving, high-temperature and corrosion-resistant, with excellent thermal insulation, meeting all rapid sintering requirements.

2. Extremely low thermal expansion coefficient, high-temperature resistance, excellent chemical stability, and excellent electrical insulation.

3. The entire furnace body utilizes a double-layer inner shell structure with an air gap in between. Even at furnace temperatures as high as 1200°C, the furnace surface remains safe to the touch without feeling hot.

4. The flange utilizes double-ring sealing technology, effectively improving its atmospheric resistance. The flange is equipped with a variety of connectors for connecting resistance vacuum gauges and vacuum bellows, and can be designed as an easily removable hinge.

5. The heating element utilizes high-quality embedded alloy heating wire, offering high heating efficiency, high-temperature resistance, oxidation resistance, corrosion resistance, rapid heating, long life, minimal high-temperature deformation, and easy installation and maintenance.

6. Easy operation, precise, reliable, and safe temperature control. Multi-stage programmable control simplifies complex testing processes and enables truly automated control and operation.