UFC 3-280-03
23 JULY 2003
dewatering effects. Therefore, centrifugal pumps are usually not recommended for filter
press systems.
2-4.3.2.6 Following are several parameters that should be considered when selecting
the appropriate pump:
Filling time and capabilities (i.e., pressure 690 to 1550 kPa [100 to 225 psi]).
Sludge characteristics (i.e., solids content, pH, particle size, abrasiveness,
temperature, and chemical content).
Suction conditions.
Size of press.
Available power source.
2-4.3.2.7 A general guide for pump applications is presented in Table 2-7. Additional
information and descriptions of sludge pumping equipment are provided in the docu-
ment Design of Municipal Wastewater Treatment Plants (WEF 1992) and are also
available from equipment manufacturers such as those listed in Appendix A.
Table 2-7. General application guide for the selection of sludge pumps.
Sludge Characteristics
Non-aggressive
Chemically
Non-abrasive
Aggressive
Abrasive
Pressure Required (kPa)1
690
1550
690
1550
690
1550
690
1550
Type of Pump
Progressive Cavity8
X2
X
X
X
X
3
3
Piston
X
X
4
X4
Piston Membrane
X
X
X5
X6
X2,5
X5
X5
Air Operated
X
X
Diaphragm
Centrifugal7
X4
X4
X
Source: Complied from filter press manufacturers listed in Appendix A.
Notes: The pumps indicated with an "X" are typically recommended for the application listed.
1
Pressure conversions: 690 kPa=100 psi, 1550 kPa=225 psi.
2
Stainless steel lining recommended.
3
Typically recommended up to 6 L/s (100 gpm).
8
Abrasive slurries--consult with pump manufacturer; slow
4
Rubber lining recommended.
operating speeds are recommended when used in this type
5
of application.
2:1 pressure ratio required.
6
Plastic lining recommended.
7
Recommended for only fast fill applications.
2-4.3.3
Press Prefilling. Before the sludge is pumped into the filter press, the press
should be filled with effluent water to remove any trapped air. This step eliminates the
potential for non-uniform cake distribution caused by partial filling of the press with
sludge during a filtration cycle.
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