Integral numerical investigation on combustion of blended coal in revolving cement kiln

Blended coal that consists of 70% anthracite and 30% bituminous coal is che aper than pure bituminous coal, but it is very difficult to burn in the rev olving cement kiln. To burn the blended coal, a new kind of burner, which i s called the burner with velocity difference jets, is used. The combustion processes in the revolving cement kiln are simulated by means of improved m ulti-fluid model for two-phase turbulent flows with reaction. The better bu rner construction is decided by simulation, which should not only ensure th e ignition and stable combustion for blended coal but also restrain the exp ansion of pulverized coal flow and make flame not touch the slagging layer of kiln. The results of integral simulation show that the ignition of blend ed coal is slower than that of bituminous coal, but the flame of blended co al is longer than that of bituminous coat. Thus the use of blended coal not only reduces the cost but also suits wet kiln better.