Application scope and safety points of thermal oil heater

Applications and Safety Tips for Thermal Oil Heaters

A thermal oil heater is a common term for an "organic heat transfer medium." A thermal oil heater is a special type of boiler whose working medium (heat medium) is thermal oil, not water. Using thermal oil as the working medium offers the advantage of achieving higher operating temperatures at lower operating pressures, thus meeting industrial needs for low-pressure, high-temperature heat sources. For example, to raise the temperature of thermal oil to 300°C at a low pressure of 0.8 MPa, the water pressure must be simultaneously increased to a high pressure of 9 MPa. Similar to conventional boilers-steam boilers and hot water boilers-thermal oil heaters can be divided into vapor-phase and liquid-phase types. Currently, liquid-phase thermal oil heaters are the most commonly used in China.

Thermal oil is an organic heat transfer medium and is classified into two categories: mineral oil and synthetic. Mineral oil is the most commonly used type in China. Generally speaking, thermal oil belongs to the lubricant family of petroleum products and is chemically stable, unlike lighter oils, which can ignite and burn easily. From a practical and safety perspective, the main characteristics of thermal oil electric heaters are:

1. Within the allowable temperature range, they offer excellent thermal stability, low coking, and a long service life.

2. Within the allowable temperature range, they offer excellent thermal conductivity, flowability, and pumpability.

3. They are low-toxic and odorless, non-corrosive to equipment, and have minimal environmental impact.

4. Thermal oil heaters have a low freezing point, a high boiling point, and a low content of low-boiling-point components. Within the allowable temperature range, their vapor pressure is low, resulting in minimal evaporation losses.

5. At temperatures above 70°C, they are strongly oxidized when in contact with air. Therefore, the heated working system must be sealed, and contact with air is only permitted at temperatures below 70°C.

6. They expand significantly in volume upon heating, with a rate far greater than that of water. With a temperature rise of 100°C, the volume expansion rate can reach 8-10%.

7. Overheating can cause cracking or condensation, resulting in coking or carbon deposits in containers and pipes.

8. When mixed with water or low-boiling-point components, the vapor pressure increases significantly upon heating.

9. Its flash point, ignition point, and auto-ignition point are all high. It will not ignite or burn at the permissible temperature and in a sealed state.