The invention relates to a wood gas boiler having a boiler wall and a boiler bottom, at least one device for supplying air and at least one grating being arranged within the boiler wall and above the boiler bottom, and wood gas being produced in a firebed from wood chips on the grating, which wood gas can be extracted and/or conducted outwards, there being in the region of the firebed a star having a plurality of arms which extend in a star shape towards the boiler wall and can each be rotated about a rotational axis running radially with respect to the central vertical axis of the star.

An improved fire grate may provide fresh oxygen rich air to a secondary combustion zone, created by the improved fire grate, of a combustion chamber where a combustion gas stream is typically oxygen starved assisting in the burning process of incompletely burned particulates and reducing other harmful emissions. A baffle plate may be introduced in the secondary combustion zone to increase a combustion chamber temperature, encourage mixing of oxygen starved air with oxygen rich air and increase a residence time of the combustion gas within the combustion chamber. These aspects of the baffle plate promote more efficient burning of the biomass/fuel. Additionally, log lighter(s) may be disposed in the secondary combustion zone to increase a temperature of the combustion chamber for the purposes of reducing harmful emissions. The improved fire grate may be horizontally and vertically adjusted to fit within different sized fireplace combustion chambers.

An improved fire grate may provide fresh oxygen rich air to a secondary combustion zone, created by the improved fire grate, of a combustion chamber where a combustion gas stream is typically oxygen starved assisting in the burning process of incompletely burned particulates and reducing other harmful emissions. A baffle plate may be introduced in the secondary combustion zone to increase a combustion chamber temperature, encourage mixing of oxygen starved air with oxygen rich air and increase a residence time of the combustion gas within the combustion chamber. These aspects of the baffle plate promote more efficient burning of the biomass/fuel. Additionally, log lighter(s) may be disposed in the secondary combustion zone to increase a temperature of the combustion chamber for the purposes of reducing harmful emissions. The improved fire grate may be horizontally and vertically adjusted to fit within different sized fireplace combustion chambers.