What are electric heating radiant tubes? What are the types of electric heating radiant tubes? What are their advantages?

An electric radiant tube converts lost electrical energy into a heat source to electrically heat items. During operation, a low-temperature fluid medium is introduced into the tube's inlet under pressure through a channel. This fluid flows along a designated heat exchange path within the heated item, using a path designed using the fundamental principles of fluid thermodynamics. This transfers the high-temperature heat generated by the tube's heating element during operation, raising the temperature of the heated medium within the tube, and ensuring that the outlet of the tube receives the desired high-temperature medium.

The tube's internal control system automatically adjusts the tube's output power based on the output temperature sensor signal, ensuring a uniform medium temperature at the outlet. If the element overheats, a separate overheat protection device immediately shuts off the heating power, preventing the heated item from overheating and potentially causing coking, deterioration, or carbonization. In severe cases, this can lead to element burnout, effectively extending the tube's lifespan.

What are the different types of electric radiant tubes?

1. Linear spiral-wound electric heating radiant tube

This electric heating radiant tube consists of a heat-resistant alloy steel casing and a heater. The heater is generally composed of an electric heating wire wound on a heat-resistant insulating ceramic tube core with spiral grooves.

2. Strip-shaped spiral-wound electric heating radiant tube

The structure of this heater is basically the same as the first structure, except that the electric heating element is wound with a resistance strip, and the tube core is mostly composed of multiple grouped tube cores. Under the same surface load, the heat radiation surface is large and the material can be saved. Generally, high-power electric heating radiant tubes adopt this form.

3. Axial wavy cage-type electric heating radiant tube (commonly known as squirrel-cage electric heating radiant tube)
The structure is to bend the resistance wire (strip) of the electric heating element into a "U" shape and string it into multiple insulating and high-temperature resistant ceramic support plates, and fix it in the middle with a heat-resistant rod. This type of radiant tube has a long service life.

What are the advantages of electric heating radiant tubes?

(1) It can ensure the controllability of the atmosphere in the furnace.

(2) Installation, testing and maintenance are very convenient, all carried out outside the furnace. There is no need to shut down or cool the furnace temperature to maintain and replace the electric heating device. Under normal production conditions, replacement only takes about 10 minutes, which greatly reduces labor intensity and improves productivity.

(3) Temperature control, installation and maintenance are convenient, and it is easy to seal.

(4) Strong heating capacity and high efficiency

(5) Compact structure, stable performance, single power supply, and service life is several times that of ordinary electric heating tubes. Therefore, it is an ideal product for tunnel kilns of drying equipment.