High temperature Tube Furnace Operating principle: The thermocouple converts the furnace temperature into a voltage signal, which is then applied to the microcomputer-based temperature control regulator. The regulator compares this signal with the programmed setpoint and outputs an adjustable control signal. This adjustable signal subsequently controls the trigger circuit, which in turn triggers the voltage regulator, thereby regulating the furnace voltage and, consequently, the furnace temperature.

Structure of the tubular electric furnace body and furnace chamber:

The design and adoption of advanced technologies ensure a novel furnace appearance and a rational structural configuration. The outer shell is fabricated from nationally standardized steel and features a powder-coated finish that offers excellent resistance to high temperatures, weathering, oxidation, acids, and alkalis. Carefully selected color schemes enhance the product’s aesthetic appeal while ensuring durability. The furnace chamber is entirely constructed from imported Morgan fiber, with the lining assembled from multiple refractory fiber modules, which effectively minimizes thermal-shock-induced cracking. The heating elements in the tubular electric furnace are either silicon-carbide rods or silicon-molybdenum rods, evenly distributed on the left and right sides of the furnace chamber.

Silicon-molybdenum rod electric heating elements are resistance heating elements based on molybdenum silicide. When sintered molybdenum silicide products are heated to high temperatures in an oxidizing atmosphere, a dense quartz glass film forms on their surface, which prevents further oxidation of the material. Consequently, silicon-molybdenum rod elements exhibit exceptional high-temperature oxidation resistance. In an oxidizing atmosphere, the maximum service temperature is 1750°C. The electrical resistance of silicon-molybdenum rod elements remains constant over their service life (resistance increases with rising temperature), meaning they do not age; therefore, new and old elements can be used in combination. Like other ceramic products, silicon-molybdenum rod elements are brittle at room temperature and prone to fracture, but such failures can be avoided through proper use and correct installation.

Silicon carbide rods are non-metallic high-temperature electric heating elements in rod form, manufactured by lightly processing green, high-quality silicon carbide material as the primary raw material, followed by high-temperature siliconization and crystallization. Compared with metallic heating elements, these rods offer advantages such as higher operating temperatures, excellent oxidation and corrosion resistance, longer service life, minimal deformation, and convenient installation and maintenance. Silicon carbide rods have a relatively high resistivity; when heated in air, the surface temperature of the heating section can reach 1450℃; the characteristic curve shows negative values from room temperature to 800℃ and positive values above 800℃. Silicon carbide rods exhibit excellent chemical stability: acids have no effect on them, but alkalis and alkaline earth metal oxides can corrode them under certain temperature conditions. At high temperatures, steam, hydrogen, halogens, sulfur, and other substances can also cause oxidation and corrosion. To ensure uniform furnace temperature and even load distribution on the rods, resistance matching must be performed before installation, with resistance differences kept within 10%. During long-term operation of the electric furnace, if individual rods are damaged for various reasons and need to be replaced, the replacement rods should be selected based on the current increase in resistance, ensuring that their resistance is appropriately matched; random selection of new rods for replacement is strictly prohibited. If a large number of rods are damaged or the resistance has increased excessively, making it impossible to achieve the required furnace temperature, the entire set of rods should be replaced with new ones. The removed rods should then be re-measured for resistance and matched accordingly. Introduction to the GWL vertical tubular electric furnace for low-temperature zones: through meticulous design, this furnace overcomes issues such as center deviation, center of gravity shift, interference, 180-degree rotation, and upward migration of the high-temperature zone, and incorporates features such as assisted rotating bearings.

1. Control accuracy: 1°C; Furnace temperature uniformity: 1°C (depending on the size of the heating chamber);

2. Microcomputer control for convenient operation, programmability, and automatic heating, heat preservation, and cooling.

3. The furnace tubes are made of 99% alumina ceramic;

4. Stainless steel metal flange seal (with double rubber gaskets);

5. The furnace body temperature is close to room temperature;

6. Dual-loop protection (including overpressure, overcurrent, overheating, overpressure, thermocouple failure, rod breakage, and power failure protection, among others);

7. Imported refractory materials with excellent thermal insulation performance and high temperature resistance;

8. High vacuum degree: -0.1 MPa;

9. Compatible with multiple gases (oxygen, nitrogen, argon, hydrogen, etc.);

10. Temperature classes: 1400℃, 1600℃, and 1700℃—three sets of gas-control cabinet parameters for GWL tubular electric furnaces.

Tube-type electric furnace http://www.ctjzh.com/