TM 5-814-3/AFM 88-11, Volume III
(f) Advantages and disadvantages. Some of the advantages and disadvantages of a solid-bowl
decanter centrifuge compared with other dewatering processes are presented in table 16-9. The ability to be
used for thickening or dewatering provides flexibility and is a major advantage of solid bowl centrifuges. For
example, a centrifuge can be used to thicken ahead of a filter press, reducing chemical usage and increasing
solids throughput. During periods of downtime of the filter press, the solid bowl centrifuge can serve as an
alternate dewatering device. Another advantage of the solid bowl centrifuge for larger plants is the availability
of equipment with the largest sludge throughput capability for single units of any type of dewatering equip-
ment. The larger centrifuges are capable of handling 300 to 700 gallons per minute per unit, depending on
the sludge's characteristics. The centrifuge also has the ability to handle higher-than-design loadings, such
as a temporary increase in hydraulic loading or solids concentration, and the percent solids recovery can
usually be maintained with the addition of more polymer (while the cake solids concentration will drop
slightly, the centrifuge will stay online). Solid bowl centrifuges are typically capable of dewatering a 50:50
mixture of anaerobically digested primary and secondary sludges to a 15-21 percent solids concentration.
Table 16-10 lists common design shortcomings and their solutions.
16-17
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