Mechanical mixing axial variation

Tubular flow reactors are usually operated under steady conditions so that, at any point, physical and chemical properties do not vary with time. Unlike the batch and tank flow reactors, there is no mechanical mixing. Thus, the state of the reacting fluid will vary from point to point in the system, and this variation may be in both the radial and axial direction. The describing equations are then differential, with position as the independent variable. 

Measurements for water containing 0.2% ethanol, the addition of which was found to influence markedly the gas holdup (see Section V,B,3), indicate that variation of surface tension has no significant effect upon axial mixing. The results for 2-mm spheres could not be correlated by a similar expression. It is proposed in that work that the flow mechanism in this case is significantly different because of the higher ratio between bubble size and particle size. 

Several groups (84-86) have extended the similarity analysis of Burton et al. (73) to the case in which an axial magnetic field is imposed on the melt with sufficient strength such that Ha >> 1 and N 1. With these limits, a closed-form asymptotic expression describes the variation in the flow field across the thin 0(Ha 1/2) Hartmann layer adjacent to the disk. Axial solute segregation across this layer was analyzed by assuming that the melt outside of the Hartmann layers is well mixed. The effective segregation coefficient approaches 1 when the field strength is increased, as expected for any mechanism that damps convection near the crystal. 

To allow good fuels mixing to control the flame shape and avoiding the formation of dual flames, the burner should be adjustable under working conditions. The burner tip adjustments by variation of the cross sections of the axial and swirl air charmels are done mechanically or by a hydraulic mechanism. 

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