Boilers with fuel feeder are becoming more and more popular due to their automated operation. Without the user’s intervention, the furnace achieves continuous combustion, and its operation is limited only to regular refilling of the fuel in the feeder.
The fuel feeder in the boiler is driven by an electric motor, so it requires a constant power supply. The fuel is delivered to the furnace at the bottom of the stove. Then the fuel is pushed through the feeder, which also automatically pushes the ash from the burner, which remains after burning the previously delivered portion. It should be remembered, however, that too large pieces of coal and impurities contained therein may contribute to noisier operation of the feeder, which has to crush them beforehand. In the case of very large pieces of coal, even blockage and stopping the boiler operation may occur, and restarting requires human intervention.
The air necessary for combustion is supplied by a fan. The intensity of the airflow is determined by the speed of the feeder, and is regulated by an electronic regulator, which can cooperate with temperature sensors inside the room (room controller) or outside the building (weather control).
In the fuel tank integrated with the boiler there is usually enough fuel for several hours of operation of the device during severe frost and even for several days when the outside temperature is moderate. Boilers can be equipped with screw or piston (drawer) feeders. Boilers with a feeder can be optimized for burning coal dust, but it can also be fired with coal of larger granulation, briquette and wood pellets.
Piston boiler fuel is delivered to the combustion chamber in portions, which means that after burning one part of the fuel, the piston delivers another portion. The piston should work without interruption, so that there is no need to reignite the fuel after refilling the boiler. The operation of the device is controlled by an electronic controller.