During the design and selection stage, site conditions must be checked first, and then the structural form and explosion-proof grade of the explosion-proof electric heater can be determined. If there is any misjudgment in the hazardous area classification, medium type, or maximum operating temperature, the explosion-proof grade may be mismatched, affecting subsequent safety supervision acceptance. The selection of the BGY15 explosion-proof electric heater can be confirmed item by item in the following order.
The common explosion-proof types are ExdI and ExdIIBT4. ExdI is suitable for non-coal-mining working faces in coal mines; ExdIIBT4 is used in factories and is suitable for explosive gas mixtures in environments of Groups IIA and IIB, T1 to T4. If hydrogen, acetylene, or other Group IIC gases are present on site, or if the ambient temperature group exceeds T4, products with the corresponding grade should be selected separately, avoiding judgment based only on equipment appearance. During selection, priority should be given to confirming parameters such as the on-site hazardous area classification, medium type (gas/liquid/dust), and maximum operating temperature.
The equipment uses a path designed according to the principles of fluid thermodynamics. The low-temperature fluid medium enters its inlet through a pipeline under pressure, flows along a specific heat exchange channel inside the electric heating vessel, and takes away the high-temperature thermal energy generated during operation of the electric heating element, thereby raising the temperature of the heated medium, and the outlet of the electric heater obtains the high-temperature medium required by the process. When the medium is thermal oil, attention should be paid to the flow rate and the heat flux density of the heat exchange surface to prevent local overheating from causing oil degradation.
The installation location should facilitate maintenance and pressure relief, and the direction of the wiring cavity should avoid accumulated water and material splashing. Temperature, flow, and over-temperature protection should preferably be included in the control interlock, and the interlock action values should be set according to the upper process limits.
