Abstract: A device for determining the topography of the burden surface in a shaft furnace (10), the device comprising a radar device (20) that scans the burden surface (18) and has an antenna device (22) arranged in the area of a furnace cover (13), the antenna device being arranged on an axis of rotation (24) that is inclined in relation to a vertical axis (15) of the shaft furnace at an angle of inclination ? and being rotatable about the axis of rotation by means of a drive device in such a manner that a radar fan beam (28) formed by the emitted radar radiation of the antenna device is incident upon the burden surface along a profile line p and sweeps across the burden surface as the antenna device rotates.

Abstract: The invention relates to a device for determining the topography of the burden surface in a shaft furnace (10), the device comprising a radar device (20) that scans the burden surface (18) and has an antenna device (22) arranged in the area of a furnace cover (13), the antenna device being arranged on an axis of rotation (24) that is inclined in relation to a vertical axis (15) of the shaft furnace at an angle of inclination a and being rotatable about the axis of rotation by means of a drive device in such a manner that a radar fan beam (28) formed by the emitted radar radiation of the antenna device is incident upon the burden surface along a profile line p and sweeps across the burden surface as the antenna device rotates.

Abstract: The invention relates to a diaphragm device (38) and to a method for protecting an optical observation opening (39), in particular for protecting the observation opening against contaminants from a dirty atmosphere (35) in a blast furnace or the like, having a nozzle unit and a purging gas chamber (43), wherein the nozzle unit forms a diaphragm aperture (26) for the observation opening and is used to form a purging gas flow, wherein the purging gas chamber is formed between an optical surface (41) of the observation opening and the diaphragm aperture. A purging gas is applied to the purging gas chamber and purging gas can be led through the diaphragm aperture into the dirty atmosphere, wherein the nozzle unit has a flow guiding device (31, 49) which effects guidance of the flow of purging gas escaping into the dirty atmosphere.