By making the coal particles form a spiral flow, it enables the prolonged retention of the coal particles inside the gasifier that is necessary for their reactions. This in turn means that a high gasification efficiency can be obtained.
It deploys burners in two sets that form an upper and a lower stage. By appropriately distributing the volume of oxygen that is fed to the upper and to the lower stage burners, it enables the lower stage burners to produce the necessary heat for melting the ash and for the coal gasification reactions.
The upper stage burners make use of the heat produced by the lower stage burners to induce gasification reactions in the coal, thus realizing high overall gasification efficiency.