Tumbling Drum

As Che water wheel rotates, crushed limestone packed inside its hub tumbles and abrades to fines that are flushed into the acidic flow. In operation, water leaving a tumbling drum is at first milky white, then clarifies as the fines dissolve. 6 

The neutralization capacity of a tumbling drum equates to fines production per unit flow, which depends on the energy expended per unit flow to tumble the stone, and on the hardness of the stone. Energy expended per unit flow varies with the shroud diameter, KD, and the efficiency of the water wheel, as discussed above. Stone hardness is determined by the Los Angeles abrasion rating, A, a road stone test. Experience with tumbling drums indicates an acidity neutralization capacity of 3 

For the Walker mine pilot tumbling drum K - 1.58. A loss factor, /, higher than 2 may be warranted, e.g., / - 3, for which K - 1.71 by Eq. 2. A higher-efficiency water wheel (with lower K and more blades) would stall unless the drum diameter were suitably smaller than the water wheel hub diameter, or precautions taken to avoid a depth of stone in the drum near half-full. 

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Pearson, F.H. and A.J. McDonnell, "Limestone-Packed Tumbling Drums for Acidity Reduction," Journal of Water Pollution Control Federation, 50, 4, 722-733, 1978. 

Water wheel drives tumbling drum at high flow, showing Jabsco chemical feed pump. 

Continuous sintering of fine ore and dusts. Burden preparation in tumbling drums. 

At some point you will need to look at details of the interaction of the product with the system, in our washing machine, textile, water and detergent are contacted in a tumbling drum (Figure 4-8). The textile tumbles forward and backward. With a proper textile load, there is not much free water in the drum the wet textile takes up water when stretched and releases it when bended. This allows detergent to move into the textile, and the dirt to move out. 

At the present time, mechanisms for segregation even in the simple tumbling drum remain obscure, and work on more complex and industrially common blender geometries is extremely limited. Three distinct types of demixing are moderately well characterized in tumblers. They are radial demixing, axial demixing, and competitive patterned demixing. We describe each of these in turn. 

Many different methods of separation are feasible. The simplest employ tumble drums or shaking contraptions. In those cases where a continuous string of briquettes is produced, breakers, e.g. such as shown in Figure 297, can be installed. 

Forward movement of particulate solids to the discharge end of tumbling drums or fluid beds, caused by a continuous particle feed and optionally assisted by downsloping the drum or the application of gil plates in fluid beds. 

Tumble drum length + 2i in Slurry return to reservoir <---------- ... 

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