Self-limiting temperature electric heating tapes are widely used in chemical production.

In practical applications, two temperature points should generally be considered for materials transported or stored in the chemical industry, one of which is the permissible minimum temperature, for example: freezing point, crystallization point, etc. D., and the other is the permissible maximum temperature., such as: boiling point, decomposition temperature wait. Generally, the safest storage and transportation temperature is between these two temperatures. For example, the melting point of glacial acid is 16.7 ° C, and its volume when solidified increases so much that it can break the vessel; at the same time, the flash point is 42.78 ° C, and the boiling point is 118 ° C. And volatile and caustic. Therefore, when storing and transporting glacial acetic acid, it is usually required to maintain a temperature of 20-30 °C. Neither too high nor too low.

The ideal electric heating method assumes that the amount of heat compensation can change according to the change in heat loss. For example, the temperature in summer and winter is different, and the heat loss of the pipeline is also different. It is best to change the amount of heat compensation accordingly to keep the material temperature stable.

The earliest method of heating is average heating, especially steam heating. However, due to the disadvantages of steam electric heating, such as high energy consumption, labor intensity of installation and maintenance, etc. D., it is gradually being replaced by electric heating.

In the early 1970 s, a self-limiting temperature electric heating belt (also called an electric heating belt) began to be made from conductive polymer composite materials with PTC characteristics. Electric heating belt has the following characteristics: ① It can automatically limit the temperature during heating; ② It can automatically adjust the output power according to the temperature of the system being heated; ③ The above functions can be performed in parts and independently; for example, for the same pipeline in a certain part, the temperature is lower (If it is outdoors), the heating belt automatically increases the output power in this area; if the temperature in the other part is higher (such as indoors), the heating belt will automatically reduce the power output in this area. ④Can be arbitrarily truncated or arbitrarily extended within a certain length range; \ n⑤Any overlap without high temperature hot spots is allowed.

Reliability is a prerequisite for industrial products and is closely related to the operating costs of products. This is an important indicator of product quality and the first choice of people when choosing goods. The self-limiting temperature heating belt is composed of conductive polymer materials, and its reliability is mainly reflected in two aspects: first, the physical and chemical stability of the polymer material, and second, the stability of the formed conductive network. We can slow down the chemical degradation reaction of polymer materials by adding antioxidants; through radiation cross-linking, polymer chains are interconnected to stabilize physical properties and maintain the stability of the conductive network.

Self-limiting temperature heating belt is the general heating, the heating surface is large, there are no high-temperature hot spots, and the temperature will not exceed the maximum surface temperature; in addition, the heating belt consists of many parallel structures, even if there is local damage, it will not affect the use of other parts.

In the industrial sector, the choice of heating methods for pipelines and containers should, firstly, be weighed and compared in terms of economics, technology, safety and reliability, and secondly, factors such as installation and use, usability, and whether it can be automatically managed. Self-limiting temperature electric heating belt, power can be adjusted according to temperature to ensure its technological progress; maximum surface temperature ensures its safety; overall heating and parallel structure ensure its reliability. Self-limiting temperature electric heating technology is a very promising technology.