Abstract: In this paper,the relationship between the slag gasifier nozzle angle,nozzle diameter,jet velocity and turbulent flow region depth in the fixed bed gasifier were investigated.The study was carried out on a two-dimensional cold-state experimental model of industrial-scale gasifier established according to similarity theory.The gas velocity distribution in the granular bed was measured by the precision pitot tube,and the data was processed by dimensionless method.Results show that jet penetration depth and the quadratic of nozzle diameter are strongly related.Nozzle jet depth presents a trend of increase before decrease with the increase of nozzle angle.Jet depth is the largest when installing angle varys from 17° to 20°.The jet depth increases with the increasing of jet gas velocity.The dimensionless relation of gasification agent nozzle angle,jet velocity,nozzle diameter and turbulent zone depth are elucidated.