Explosion-proof electric heater is a heating equipment specially designed for flammable and explosive hazardous environments (such as petroleum, chemical, natural gas, pharmaceutical and other industries). Through special structural design and material selection, it ensures that no electric sparks or high-temperature surfaces sufficient to ignite surrounding explosive gases, vapors or dusts will be generated during operation. The following is a summary of core information about explosion-proof electric heaters: 1. Working Principle Energy Conversion: Uses electric current passing through resistance elements (such as heating wires, PTC ceramics, etc.) to generate heat energy. Heat Transfer: Heat is transferred to the object being heated through a heat-conducting medium (such as fluid, air, or solid contact surfaces). Explosion-proof Core: Flameproof Type (Ex d): Encloses components that may produce sparks in a sturdy housing. Even if an internal explosion occurs, the housing can withstand the pressure and prevent flame propagation to the external environment. Increased Safety Type (Ex e): Applies additional protective measures (such as enhanced insulation, temperature rise limitation) to components that do not produce sparks, arcs, or dangerous high temperatures during normal operation, preventing hazards under fault conditions. Intrinsic Safety Type (Ex i): Limits the energy (voltage and current) in the circuit so that sparks or thermal effects produced under any fault condition are insufficient to ignite explosive mixtures. Pressurized Type (Ex p): Fills the equipment housing with protective gas, maintaining internal pressure higher than the external environmental pressure to prevent external explosive gases from entering. 2. Main Application Fields Petrochemical Industry: Crude oil heating, pipeline heat tracing, reactor temperature control, storage tank insulation. Natural Gas Industry: Wellhead heating, heating in natural gas desulfurization and decarburization processes. Pharmaceutical and Food: Heating processes in clean environments where flammable solvents may exist. Dust Environments: Places with combustible dust such as flour mills, coal powder preparation, etc. 3. Key Standards and Certifications (as of 2026) In the Chinese and international markets, explosion-proof electric heaters must comply with strict standards and certification requirements: Chinese National Standards (GB): GB/T 34663-2017: "General Technical Requirements for Resistance Heaters for Explosive Gas Atmospheres". This standard has detailed provisions on material selection, structural design (sealing, heat dissipation), temperature control systems, etc., and new implementation guidelines were interpreted in 2025-2026 with the trends of environmental protection and intelligence. JB/T 7836.3-2005: For explosion-proof finned tube electric heaters used in motors. GB 3836 series: General standards for explosive atmospheres (corresponding to international IEC 60079 series). Compulsory Product Certification (CCC): Since October 1, 2020, explosion-proof electrical equipment has been included in the China CCC certification catalog. As of March 2026, products without CCC certification and marking shall not leave the factory, be sold, or be used. The certification catalog covers 18 categories of products including electric heaters, with implementation standards unified to the 2021 version and relevant latest amendments. International Standards: IEC 60079 series: International Electrotechnical Commission standards, widely recognized globally. ATEX (EU) and UL/FM (North America) certifications: Export products usually need to have these certifications. 4. Industry Trends in 2025-2026 Intelligent Upgrade: Integration of intelligent temperature control systems, support for DCS (Distributed Control System) remote monitoring, real-time power adjustment, and fault self-diagnosis functions. Green and Environmental Protection: Responding to environmental policies, adopting more efficient and recyclable green materials to reduce energy consumption. Safety Standard Enhancement: With the revision of national standards such as "Safety Requirements for Industrial Electric Heating Devices" (e.g., the revision plan released in 2026), higher requirements are placed on the general safety specifications of equipment, emphasizing full life cycle safety management. Customization Needs: Increased demand for customized designs for different working conditions (such as high corrosion, extreme cold, high pressure) to address product homogenization issues. 5. Selection and Maintenance Suggestions Selection: Must select heaters with corresponding explosion-proof level and temperature class based on specific hazardous area classification (Zone 0, 1, 2 or Zone 20, 21, 22), category of explosive substance (gas/dust), and temperature class (T1-T6). Installation: Must be carried out strictly according to the instructions, ensuring good grounding, reliable sealing of cable entry devices, and avoiding mechanical damage. Maintenance: Regularly inspect housing integrity, terminal tightening, temperature control system sensitivity, and strictly prohibit opening the cover while energized.
