spiral or other descending ridges are positioned on the interior surface of the constricted cylindrical opening of the venturi a tube through which reaction gases pass is centrally disposed within the constricted cylindrical opening to permit variable and increased rates of agglomerate discharge with improved separation and classification of the solid materials application_number US 40822682 A description fig1 is a schematic drawing of a prior art fluidized bed gasifying apparatus or device which includes conventional means for agglomerating ash or particulate matter in the fluidized bed as generally described in jequier et al u s pat no 2 906 608 previously referenced briefly the device includes an upright vessel 10 within which a fluidized bed 12 of coal char is retained at conventional temperature and pressures for the conversion of the coal to gaseous products specifically pulverized fresh feed coal enters via line 14 and is contained within the bottom portion of the vessel or reactor 10 as a fluid bed 12 the coal within the bed 12 is then converted by reaction with steam and air or oxygen to gaseous fuel components these gaseous fuel components pass from the vessel 10 through a discharge line 16 a shaped sloped grid 18 is provided within the vessel 10 at the bottom of the bed 12 air or oxygen and steam enter through a line 20 and pass through openings in the grid 18 to assist in maintenance of the bed 12 in a fluidized state the ash contained in the feed coal within the.