What device heats the oil further before it enters the burner for combustion?

The pre-heater is the correct device that heats the oil further before it enters the burner for combustion. Its primary function is to raise the temperature of the oil to ensure that it reaches the optimal viscosity for efficient atomization in the burner. This is crucial because oil that is too thick can lead to incomplete combustion, resulting in lower efficiency and higher emissions.

In systems using heating oil, by preheating the fuel, operators can improve the overall combustion process, allowing for better performance and a more stable flame. Proper pre-heating also helps in minimizing the risk of carbon build-up and increases the overall reliability of the burner system.

While boilers and heat exchangers do involve heating and transferring heat in various contexts, they are not specifically designed to heat oil prior to combustion in the same specialized manner as a pre-heater. Compressors are involved in raising the pressure of gases and are not used in the oil heating process.