How to choose the carrier of thermal oil electric heater

Because the heat transfer medium undergoes long, uninterrupted cycles of heating in the furnace, it is prone to polymerization, coking, and deterioration. Therefore, the following points should be considered when selecting a heat transfer medium:
① Excellent high-temperature thermal conductivity; ② Good stability and a long service life, ensuring a service life of at least ten years; ③ The operating temperature should be below the boiling point, with a low freezing point, toxicity, and corrosiveness; ④ High initial boiling point and flash point for good performance. Most heat transfer fluids operating between 250°C and 300°C are synthetic oils, priced between 15,000 and 25,000 per cubic meter. Users can choose a different heat transfer fluid based on their needs.
The heating, dehydration, and exhaust processes of a heat transfer oil furnace are critical stages of operation and require particular attention. Specifically, heating should be stopped when the temperature is between 95°C and 110°C or 210°C and 230°C, and the temperature should be maintained for a period of time. Generally, this process takes approximately 48 hours. Once the thermal oil temperature exceeds 95°C, the remaining moisture and low-volatility components in the oil begin to evaporate.

Gases will escape from the vent on the expansion tank. Therefore, the heating rate for dehydration and exhaust should not exceed 5°C/hour. Generally, when the thermal oil is heated to 105-130°C, the exhaust volume is higher. At this time, the exhaust from the expansion tank vent, as well as the operation of the circulating oil pump and pressure gauge, should be highly emphasized.

Once the thermal oil temperature reaches approximately 200°C, the equipment and the entire system should be thoroughly inspected, and all bolted connections should be tightened immediately to prevent leaks caused by uneven thermal expansion. When the thermal oil boiler is ignited and heated, some of the evaporated water converts to vapor and enters the expansion tank through the expansion tube. Another portion converts to gas and is discharged through the drain pipe. Still another portion condenses into liquid and sinks to the bottom of the tank.

During heating, the drain pipe under the expansion tank should be opened at all times to drain the condensed water. After dehydration and exhaust, continue heating at a rate of 20°C/hour. Heating should be stopped if the temperature reaches approximately 210°C. At this point, the primary process is to remove the light components from the thermal oil. The time required for this removal should be determined based on the brand and quality of the thermal oil.

If no gas is emitted from the thermal oil heater's exhaust pipe and the circulating thermal oil pump pressure is relatively stable, the temperature can continue to be raised at a rate of less than 10°C/hour to 230°C. After degassing, the temperature can be raised from 230°C to the operating temperature of the thermal oil heater at a rate of 40°C/hour. At this point, a comprehensive inspection of the thermal oil heater, circulating heating system, and various supporting facilities and ancillary equipment should be conducted to ensure proper operation.