In petroleum, chemical, coal, gas and other industrial fields, the production environment is full of flammable gas, explosive dust and other dangerous substances, and ordinary electrical equipment is easy to generate electric sparks or high-temperature surfaces during operation, triggering combustion and explosion accidents. As a common heating component, cartridge heaters must have explosion-proof performance to be used in such dangerous environments. Explosion-proof cartridge heaters are specially designed according to national explosion-proof standards, providing safe and reliable heating solutions for flammable and explosive environments.
The core design of explosion-proof cartridge heaters is to eliminate all potential ignition sources, meeting the requirements of explosion-proof grades Ex d IIC T6 and Ex tD A21 IP65. First of all, the heater adopts an explosion-proof sealed structure, the end is equipped with a thickened explosion-proof junction box, which can withstand the pressure generated by internal gas explosion, and prevent the internal spark and high temperature from spreading to the outside dangerous environment. The junction box is made of cast aluminum or stainless steel, with high strength and good explosion-proof performance, and the joint is sealed with a gasket to prevent the entry of flammable gas and dust.
Secondly, the surface temperature of the explosion-proof heater is strictly controlled to be lower than the ignition temperature of flammable substances. According to different explosion-proof grades, the maximum surface temperature of the heater is limited to 85℃, 135℃, 200℃ and other grades, avoiding high-temperature surface igniting flammable gas and dust. The watt density of the heater is designed reasonably, generally not exceeding 15W/cm², to ensure that the surface temperature is controlled within a safe range, even if it operates for a long time, it will not produce overheating and ignition risks.
In terms of material and process, explosion-proof cartridge heaters are made of high-strength and high-temperature resistant materials. The sheath is made of 316 stainless steel or explosion-proof alloy, with good corrosion resistance and mechanical strength, resisting the erosion of chemical gases and dust in dangerous environments. The internal resistance wire uses high-stability nickel-chromium alloy, with low resistance drift, and the insulation material uses high-purity magnesium oxide, with good insulation and heat transfer performance. All wiring parts are tightly sealed and fixed to avoid poor contact generating electric sparks, ensuring the safety of the circuit part.
Explosion-proof cartridge heaters are widely used in various flammable and explosive scenarios: in the petroleum and chemical industry, they are used for heating of reaction kettles, pipelines and storage tanks; in the coal industry, they are used for heating of coal mine equipment and gas extraction equipment; in the gas industry, they are used for heating of gas transmission pipelines and pressure regulating stations; in the pharmaceutical and coating industry, they are used for heating of equipment in workshops with flammable dust and solvent vapor.
In addition to explosion-proof performance, these heaters also have the advantages of high heating efficiency, uniform heating and long service life. They can be customized with different power, voltage and size according to user needs, and equipped with explosion-proof temperature controllers and over-temperature protection devices to realize automatic temperature control and power cut-off in case of over-temperature, further improving the safety of use.
For enterprises in flammable and explosive environments, choosing qualified explosion-proof cartridge heaters is not only a guarantee of production safety but also a necessary requirement to meet national safety regulations. It is necessary to choose products with formal explosion-proof certification to ensure that they meet the safety standards of the use environment and avoid potential safety hazards.
