Split Tube Furnace

What is the Split Tube Furnace?

A split tube furnace opens along its length so the work tube can be placed without threading it through. It is chosen for long tubes, glass apparatus and delicate samples that must be positioned precisely.

Overview

The split furnace is hinged so that the two halves open like a clam, allowing a work tube, reactor or sample to be placed directly into the hot zone and removed the same way. This avoids threading long tubes through the bore and reduces the risk of breaking glassware or dropping a boat. The heating winding and insulation are split to match, and a latch holds the halves closed during operation. Tube diameters run 25 to 100 mm with hot zones of 200 to 600 mm, temperatures to 1200 C, and gas or vacuum connections at the ends. Because the sample can be inserted cold and then enclosed, it is convenient for reactions where positioning matters. Robust construction keeps the halves aligned and the thermocouple in contact.

How does it work?

A tube furnace surrounds a cylindrical work tube with heating elements embedded in ceramic fiber or refractory, so the sample is heated inside a controlled environment separate from the elements. The tube, usually quartz, alumina or a high-temperature alloy, passes through one or more heating zones. Gas enters one end, flows over the sample and exits the other, or a pump pulls vacuum for anaerobic work. Thermocouples measure each zone, and a PID or SCR controller holds setpoints or programmed profiles. Split designs open to place the tube without threading it, while multi-zone designs create a controlled temperature gradient. End seals, flanges and gas manifolds keep the atmosphere clean and safe, and exhaust may pass through a scrubber or bubbler.

What are the key features?

• Hinged halves that open like a clam
• Direct placement of tube, reactor or sample
• Tube diameters of 25 to 100 mm
• Hot zones of 200 to 600 mm
• Latch holding halves closed in operation
• Gas and vacuum ports at tube ends

What are the technical specifications?

A typical split tube furnace configuration offers work tube diameter of 25–100 mm, hot zone length of 200–600 mm, temperature range of RT to 1200 C, temperature uniformity of ±2–6 C, tube material of Quartz, alumina or alloy and opening type of Hinged split with latch. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Split Tube Furnace is used in reactor and glassware heating, annealing of long specimens, reactions needing precise sample placement and gas-flow calcination. Across the wider Tube Furnaces class, laboratories also deploy it for controlled-atmosphere calcination, chemical vapor deposition and catalyst reduction and activation.

Which standards and certifications apply?

Relevant standards and methods include IEC 61010-1, IEC 61010-2-010, IEC 60519-1, DIN 17052-1 and ISO 9001. Certification candidates for this model are CE, ISO 9001 manufacturing and RoHS; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Install with clearance for the hot tube ends and route exhaust gases to a safe vent, using a scrubber or bubbler for toxic or corrosive species. Use only tubes rated for the temperature and atmosphere, and never exceed the manufacturer limit, since quartz softens and alumina can crack under thermal shock. Support long tubes and avoid mechanical stress at the seals. Purge the tube before heating when air must be excluded, and check for leaks after each assembly. Calibrate the control thermocouple and profile the hot zone, and replace tubes showing cracks, devitrification or sag before failure.

How do I select the right Split Tube Furnace?

Select the split furnace when the work tube or reactor cannot easily be threaded through a solid furnace, or when fragile samples must be placed precisely. Solid designs are cheaper for short straight tubes. In the RFQ, specify tube diameter, hot zone length, opening clearance, top temperature and gas connections.

How does it compare with other Tube Furnaces variants?

Choose a tube furnace when the process needs gas flow, vacuum or a sealed environment, or when the sample must be a powder in a boat rather than a crucible in a box. Set the maximum temperature with margin above the working setpoint, and select the tube material accordingly: quartz to about 1100 C, alumina to 1600 to 1700 C, and alloys for specific atmospheres. Match the tube diameter to the sample boat, and pick one, three or five zones depending on whether a gradient or uniform hot zone is needed. Decide between solid and split designs for handling. Specify gas connections, end seals, flow meters and safety features for flammable or toxic gases.