The single-stage coal gasifiers, developing from and taking good advantage of dry-type ash-cleaning gas furnace, is a new generation of intelligent highly efficient environment-friendly products put forward by our company, in which patented rotating disk slag cleaning and automatical slag cleaning structures are used. Characteristics: Dedicated pagoda-shaped heat-resistant iron grate furnace wall always protected by slags, strong effect of slag breaking, slag loosing and ventilation, the concept that gas furnace is the same as pressure vessel basically abandoned, heating temperature autocontroled.