A brief discussion on the nine design requirements of electric heating thermal oil furnaces

### Electric-Heated Thermal Oil Furnaces: Design and Operation

#### **Overview**

Electric-heated thermal oil furnaces are advanced industrial furnaces that use electricity as a heat source and thermal oil as a heat carrier. They provide safe, energy-efficient, and high-temperature heating for various industrial processes.

#### **Design Principles and Requirements**

1. **Heat Load Margin:**

- Maintain a 10–15% margin between the heat load and the effective heat load.

2. **Design Temperature:**

- Based on operating temperature, following the "Strength Calculation of Water-Tube Boiler Components."

3. **Design Pressure:**

- Slightly higher than operating pressure, but no less than the safety valve opening pressure.

4. **Temperature Differential:**

- Keep within 30°C for system operation.

5. **Thermal Oil Flow Rate:**

- Maintain 2–4 m/s in radiant section pipes to prevent overheating and coking.

6. **Heat Intensity:**

- Ensure uniform heat intensity in boiler tubes to avoid overheating and maximize heat transfer.

7. **Exhaust Gas Temperature:**

- Control the difference between exhaust gas and thermal oil temperature (80–120°C), with exhaust gas at 350–400°C.

8. **Material Requirements:**

- Use non-ferrous metals or cast iron for pipes and accessories.

- Flanges and valves should be cast steel (nominal pressure ≥ 2.5 MPa).

- Seals must be high-temperature and oil-resistant.

9. **Drainage:**

- Equip with a low-level drain valve to completely remove residual liquid.

By adhering to these principles, electric-heated thermal oil furnaces achieve efficient, safe, and continuous heat transfer for industrial heating processes.