Three zone tube furnace up to 1100 °C with independent temperature control

The Thermo Scientific Lindberg Blue M three zone tube furnace is developed for laboratories and R&D environments requiring differentiated temperature control across the length of a process tube. As a result, this tube furnace enables more complex thermal processes, such as chemical vapor deposition, diffusion, or gas applications where preheat and main heat are separated. Specifically, the temperature range is 100 to 1100 °C, with uniformity of ± 1.0 °C over a central length of 45.7 cm. Furthermore, this line combines Moldatherm ceramic fiber insulation with double-shell construction for fast heatup and low outer surface temperatures.

Independent control of three zones

The most distinctive feature of this tube furnace is the three-zone configuration with independent zone control. Specifically, each zone is driven by its own programmable controller and thermocouple. As a result, you can create a temperature profile across the tube length, for example a lower temperature in the end zones and a higher one in the center zone. Furthermore, an important limitation applies: the maximum temperature difference between center zone and end zones is ± 50 °C, which is sufficient for most industrial applications.

Two models for different tube diameters

Specifically, you choose from two models depending on your process tube diameter:

• STF55346C-1 / STF55346COMC-1 (compact model): Tube outside diameter 1 to 3 inch (2.5 to 7.5 cm). Three heated zones of 6/12/6 inch (15.2/30.4/15.2 cm). Specifically suited for small to mid-sized samples in laboratory environments. Power 3800 W at 16 A.
• STF55666C-1 / STF55666COMC-1 (large model): Tube outside diameter 3 to 6 inch (7.5 to 15.2 cm). Three heated zones of 9/18/9 inch (22.3/45.7/22.3 cm). As a result, suited for larger samples or pilot plant applications. Power 11000 W at 46 A.

Furthermore, both models are available with an optional RS-485 communications port (suffix COMC-1) for remote monitoring and data logging from a PC.

Tube adapters for flexible tube selection

Specifically, each tube furnace ships with a set of two tube adapters at the largest specified diameter. Notably, the compact STF55346 model includes 3 inch adapters (catalog number 59545), while the large STF55666 model includes 6 inch adapters (catalog number 59558TA). As a result, you can immediately work with the maximum tube diameter, or optionally order smaller adapters to switch between different tube sizes. In addition, blank (solid) adapters are available for applications requiring sealing.

Applications in lab and industry

Specifically, this three zone tube furnace is used for more complex thermal processes, including:

• Chemical vapor deposition (CVD) with gas applications
• Diffusion processes in semiconductor materials research
• Pyrolysis with preheat and main reaction in separate zones
• Materials synthesis under controlled gas atmosphere
• Research on ceramic and metallurgical materials
• Thermal treatment of larger samples in R&D environments

In addition, this model is used in academic research laboratories, semiconductor R&D, and advanced materials science where precise temperature profiles across the length of a tube are required.

Construction and safety

Moreover, this tube furnace combines double-shell construction with variable density insulation for improved performance over conventional tube furnaces. Specifically, innovative venting and insulating air spaces create lower exterior surface temperatures, which increases operator safety. Furthermore, self-tuning PID control prevents temperature overshoot during heatup. Notably, adjustable high-limit OTP provides an additional layer of overheating protection on each zone. In addition, the long-life Type K thermocouple ensures stable temperature measurement in each zone.

Standard accessories and process tubes

Each three zone tube furnace ships with three Type K thermocouples (one per zone) and a set of two tube adapters at the largest specified diameter. However, process tubes themselves are not included. Specifically, process tubes must be ordered separately from a dedicated tube supplier. Furthermore, several materials are possible: alumina for high temperatures, mullite for general applications, quartz for optical clarity, or metallic tubes for specific processes.

Note: both models require hardwiring by a qualified technician, plus purchase of a power cord. Specifically, no plug or cable is supplied, because the high power (3800 to 11000 W) demands a fixed electrical connection.