Process and boiler installation for the combustion of solid fuel

摘要

In the combustion of solid fuel in boiler installation, the comminuted solid fuel is mixed with preheated blast air and fed to a fire space for combustion. Combustion products containing a portion of the solid and gaseous phase are conducted away from the contact gas flue. The electrically conducting fraction of the solid phase of the combustion products of the solid fuel is separated, by the action of an applied electric field, from the electrically non-conducting fraction. The electrically conducting portion of the solid phase of the combustion products is mixed with the blast air stream and fed back to the fire space for combustion. The fire space (1) of the boiler plant is connected via an intermediate flue (2) to a contact gas flue (3) and to a gravity dust-settling chamber (5). An electrostatic precipitator (10) with electrodes (11) is connected to the gravity dust settling chamber (5), and is provided with a solid phase pipe (14), connected to the fire space (1) for feeding back the electrically conducting fraction of the solid phase, and with a de-ashing pipe (13) for conducting away the ash residues. <IMAGE>