With reference to the parameter requirements of GB 3836.2 for flameproof surfaces, three sets of data should be verified first during the selection stage: rated voltage 380V, rated power 620kW, design pressure 1.6MPa, and maximum applicable temperature 300°C. The following Q&A format outlines the aspects easily overlooked during selection.
The heating elements of this product adopt a metal tubular structure. The terminal chamber and the heating chamber are isolated and sealed, and the flameproof surface parameters are implemented in accordance with GB 3836.2. During selection, the cable entry method of the terminal chamber and the medium flow direction of the heating chamber must be confirmed simultaneously; the two must not share space. The width and gap of the flameproof surface are fixed structural values and must not be ground or modified on site.
The power rating depends on the medium flow rate and temperature rise. During selection, the heat transfer oil circulation rate, inlet-outlet temperature difference, and startup time requirements should be provided, and the required power should be derived by reverse calculation through heat balance. If the medium flow rate is lower than the design value, the tube wall temperature will rise, and it is necessary to recheck whether the surface load is still within the allowable range.
The equipment is equipped with operation control and safety monitoring devices, enabling precise control of the working temperature. During selection, it is necessary to clarify the matching between the over-temperature protection setpoint and the pressure rating, and to confirm that the interlock logic covers conditions such as circulation pump shutdown and insufficient flow. 1.6MPa is the design pressure; a margin should be reserved for the actual operating pressure.
The applicable temperature is ≤300°C. During selection, it is necessary to verify the thermal stability and coking tendency of the heat transfer oil at the maximum working temperature. For long-term operation close to the upper limit, the decoking and inspection intervals should be shortened, and attention should be paid to the difference between the heating element surface temperature and the bulk medium temperature.
