Tubular electric heater is made by placing coiled heating wire (resistance wire) in a metal tube, and filling the surrounding and gap parts with insulating powder (MgO) that has good heat resistance, thermal conductivity and insulation. Both ends of the heating wire have lead-out rods or lead-out wires. It has the characteristics of simple structure, high mechanical strength, high thermal efficiency, safety and reliability, easy installation, and long service life. It is widely used in various devices such as nitre tanks, water tanks, oil tanks, acid and alkali tanks, fusible metal melting furnaces, air heating furnaces, drying furnaces, drying boxes, hot press molds, etc.
Tubular electric heater In the packaging machine, the electric heater is generally controlled by the contacts of the temperature control instrument to switch the AC power supply inside the electric heater. When the temperature of the electric heater is lower than the set temperature, the contacts of the temperature control instrument in the electric heater are closed, and the temperature of the electric heater rises. When the temperature of the electric heater is higher than the set temperature, the contacts of the temperature control instrument in the electric heater are opened, and the temperature of the electric heater drops. The on-off of the contacts of the temperature control instrument in the electric heater ensures that the electric heater works within a certain temperature range.
Once the electric heater has a burnout fault, the operator cannot determine whether the electric heater is powered off due to normal temperature rise or due to an open circuit fault. Due to the thermal inertia of the heater, the temperature inside the electric heater takes a while to drop. Tubular electric heater Thus, when the operator of the electric heater finds that the product is unqualified, hundreds or thousands of products have been wasted, affecting product quality. The electric heater open circuit detection device should be able to automatically identify the power-off due to temperature rise and the open circuit fault of the electric heater.
