During on-site handover, it is recommended to check whether the rated voltage, power, protection rating, and design documents marked on the nameplate are consistent. Taking the DYK-90 as an example, its commonly used power range is 90kW, operating voltage is 380V, protection rating is IP54, and insulation resistance is not less than 20MΩ. Magnesium oxide powder is divided into high-temperature powder and medium-temperature powder according to the operating temperature. The filling density affects thermal conductivity and insulation performance, and it must be selected according to the manufacturer's instructions.
The equipment should be installed in an area with good ventilation and no corrosive gases, and kept at a distance of not less than 0.5m from combustibles. The terminal chamber cover must face downward or sideways to avoid water accumulation. For inline pipe installation, straight pipe sections of 1.5 times the pipe diameter should be reserved before and after the heater to facilitate uniform heating of the medium. After the foundation is fixed, calibrate it with a level gauge, and the inclination should not exceed 2°.
Record the inlet and outlet temperatures, current values, and surface temperature every shift. When the current deviation exceeds ±10% of the rated value, shut down the machine and inspect the heating elements. The surface temperature must not exceed 80% of the autoignition point of the medium. If discoloration of the heater shell paint or local overheating is found, promptly investigate loose internal wiring or damp magnesium oxide powder.
When there is no temperature rise, first measure whether the three-phase resistance is balanced, then check the control circuit fuse and contactor contacts. After the leakage protection operates, do not forcibly reset it. Use a 500V megohmmeter to measure the cold insulation resistance. If it is lower than 1MΩ, it must be disassembled and dried. When replacing heating elements, use high-temperature magnesium oxide powder of the same specification for filling, and tighten the terminal screws according to the torque requirements.
In chemical pipeline heat tracing, it is used to maintain the medium temperature not lower than 15°C; in the boiler feedwater preheating stage, it can raise the water temperature from 20°C to 60°C. In welding preheating scenarios, this heater can be used to preheat alloy steel structural parts to 150–200°C before welding, and maintain 250–300°C for post-weld hydrogen removal treatment. In methanol steam heating conditions, it needs to be used with an explosion-proof control cabinet and a temperature feedback system to achieve automatic adjustment of the heat load.
