What are the key characteristics of fuel oil?

What are the key characteristics of fuel oil?

The primary characteristics of fuel oil (mazut) are its viscosity and pour point. Viscosity defines the fluid’s flow characteristics, while the pour point indicates the temperature at which the fuel oil thickens, loses its mobility (fluidity), and solidifies.

Depending on their viscosity, fuel oils are categorized into grades such as F-5, M-40, M-100, and M-200. It should be noted that higher viscosity makes the fuel more difficult to burn in steam boiler furnaces; as viscosity increases, the quality of atomization—and consequently the completeness of combustion—deteriorates.

To ensure effective atomization, the viscosity of the fuel oil must be reduced through heating.

For instance, grade M-200 fuel oil has a conventional viscosity of 200 at 50°C, whereas at 100°C, this value drops to only 6.5–9.5.

Extensive testing has demonstrated that for the proper operation of steam boiler burners, fuel oil should be heated to a temperature at which its viscosity, upon reaching the burners, is no greater than 5–7.