1. Meaning of self-limiting heating cable model
DXW-PZ/J means: The insulation material is PTC composite, the rated working voltage is 220V, and the self-limiting electric heating capacity is 20W per meter output power at 20°C.
Working principle: Two copper stranded wires are power busbars, and a self-limiting heating core material with positive temperature coefficient characteristics is extruded around the busbars. When the power is turned on, the power supply passes through the core material laterally to form a continuous parallel heating body. . The electric heating core material adopts a temperature memory conductive molecule processed by a special process. Heat is generated when current passes through the network of conductive molecules. In the cold state, current is easily passed through, generating a large amount of thermal energy. As the temperature rises, the matrix expands, the conductive molecules reduce the density of the network, cut off most of the passages, the current is reduced, and the amount of heat is reduced. Thus, the purpose of automatically controlling the temperature is achieved, so that the heating substrate exceeds the heat balance. When the temperature drops, the temperature memory conductive molecules shrink again. As a result, the circuit that was originally cut off is turned back on, the current increases again, and the heat output increases. This feature is called "temperature self-limiting characteristics", and the name "self-limiting electric heating belt" is generated.
2, product specifications and main technical indicators:
Product specifications: DXW-PZ/J self-limiting electric heating
Working voltage: 220V
Electric strength: 2.5kV/m (20°C)
The highest temperature resistance of the heating cable: 150°C
Rated calorific value: 20W/m (20°C)
Explosion-proof grade: eIIT3
Explosion-proof certificate number: 289202
The DXW self-limiting electric heating unit has the same power per unit length, and its power does not increase with the total power. It cuts arbitrarily at the scene. The "self-limiting performance" of the product exists everywhere in the entire length of the electric heating belt, thus effectively ensuring the thermal stability of the pipeline. At the same time, even if the self-limiting electric heating camps are connected to each other, there will be no overheating and burning of the electric heating belt. It can be used for heat insulation of energy pipelines below 30 °C. The starting current performance of the self-limiting electric heating belt and the PTC material are somewhat similar: a large starting current is generated at the moment of turning on the power, and the current gradually becomes smaller as the energization time is extended, and generally falls to the rated value after a few seconds. . Since the electric heating belt is generally directly activated, the maximum use length of the DXW-PZ/J self-limiting electric heating belt is 100-200m. The installation of the electric heating belt should be used in conjunction with the control electric appliance. The control electric appliance generally has overload, short circuit, grounding, leakage protection and temperature protection. The self-limiting electric heating belt can be used to solve the anti-freezing and heat preservation of pipes, valves, pump doors and pump bodies with a temperature lower than 30 °C, and is especially suitable for maintaining the process temperature of the instrument pipeline.
3. product adaptation occasions
1, instrument pipeline heating insulation
2, to prevent surface area snow, cold junction
3. Liquid line heating with strict control of operating temperature
4, plastic tube heating
5. Anti-freeze insulation at the bottom of liquefied petroleum gas or ammonia storage tank.
6, the general pipeline antifreeze.
7. Wellhead production pipe heating (replacement of water jacket furnace), water injection well antifreeze.
4, explosion-proof instructions
The self-limiting electric heating belt is designed and manufactured according to the requirements of GB3836.1-2010 and GB3836.3-2010, the "general requirements" for explosion-proof electrical equipment and the "explosion-proof electrical equipment". The explosion-proof rating is "diiBT3". Flame-retardant products are non-flammable, impact-resistant, and can be tested by sealed electric heaters. After being matched with the corresponding explosion-proof electrical appliances, they are suitable for use in the T3 group of explosive gas mixtures in Zone 1 and Zone 2. This product has passed the explosion-proof inspection of the national statutory explosion-proof mechanism.