Impeller solids mixing

Increase solids mixing. Improve powder flowahihty of feed. Increase agitation intensity (e.g., impeller speed, fluidization gas velocity, or rotation speed). 

Increasing solids mixing. Increasing excess gas velocity Increasing impeller/... 

Adding a second impeller typically has a very small effect on the just-suspended speed. In multiple-impeller systems, zoning occurs when the impeller separation is too large. The most efficient solids mixing occurs just before the... 

These mixers are particularly suited for rapid mixing of powders and granules with liquids, for dissolving resins or solids in liquids, or for removal of volatiles from pastes under vacuum. Scale-up is usually on the basis of maintaining constant peripheral velocity of the impeller. 

A semi-open impeller has exposed blades, but with a support plate or shroud on one side. Some people prefer the name semi-enelosed. These types of impeller are generally used for liquids with a small percentage of solid particles like sediment from the bottom of a tank or river, or crystals mixed with the liquid (Figure 6-17). 

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