A device for producing a
combustible gas mixture from a carbon-containing starting material, in particular from lumpy wood, comprising a feed unit (10) for feeding the starting material to a reactor (19), wherein the reactor (19) comprises at least one
oxidation zone (24) for oxidizing the starting material and a reduction zone (25) for reducing at least one
intermediate product of the oxidation, wherein a shaft seal is provided for rotating drives, and wherein a rotating shaft (4) is sealed against a dust-, pressure-, and
tar-laden
atmosphere by at least one sealing bush (7), wherein the sealing bush (7) consists of at least one
split ring (3) consisting of an inner ring (33) mounted on the shaft (4) in a rotationally fixed manner, which inner ring is connected via a sealing gap (34, 34a-d) directed in the axial direction to a radial outer ring (32) arranged in a housing (1) of the sealing bush (7), characterized in thatthat at least one further seal (2) is arranged in the housing (1) in the axial direction away from the
split ring (3), and that an annular space (31) is arranged between the
split ring (3) and the at least one further seal (2), which is filled with a
lubricant (38) which can be introduced via a fluid-conducting bore (5) connected to the annular space (31) and which penetrates and lubricates the entire sealing gap (34, 34a-d).