Coal slagging gasifier

In a coal slagging gasifier comprising:

• a gasifying vessel;
• means or introducing carbonaceous fuel into the top of said vessel for gasification thereof in said vessel;
• means for introducing a gasifying medium comprising oxygen and steam into said vessel;
• a hearth located at the bottom of said vessel and including a slag tap outlet therein for removing slag therefrom;
• a burner means positioned to direct combustion products up the slag tap outlet for maintaining a pool of molten slag in the hearth;
• a quenching chamber containing water located below said gasifying vessel into which molten slag and iron are periodically removed downwardly from said hearth through said slag tap outlet into said quenching chamber;
• venting means for producing a differential pressure between the quenching chamber and the gasifying vessel to promote tapping of the molten slag and iron, said slag tap outlet having a lowermost end providing an opening into said quenching chamber;
• the improvement which comprises a nozzle means connected to a combustion-sustaining gas source, said nozzle means comprising a tube substantially in the form of a ring substantially centered and surrounding said burner means and disposed substantially at or adjacent to the horizontal level of said opening, said tube having a plurality of ports on its underside arranged for directing a substantially annular curtain of combustion-sustaining gas substantially vertically downwards toward the water level in said quenching chamber.