Raschig rings (Fig. 8.1a). These are the oldest, cheapest, and previously most widely used packings, first patented by Dr. Raschig in Germany in 1907. The height of the ring is equal to its diameter. The rings are cut from pipes, but in case of metal they may also be rolled from metal strips (1).
Leasing rings (Fig. 8.1 b). These are similar to Raschig rings, but a partition is added across the center of the ring to increase the surface area. The partition strengthens the ring, but the improvement in efficiency due to the larger area is minor.
Berl saddles (Fig. 8.1 c). These are the original type of saddle packing. They have a smaller free gas space than Raschig and Lessing rings, but their aerodynamic shape is better, giving a lower pressure drop and higher capacity than Raschig and Lessing rings.
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