Device
| Main advantages | Main disadvantages
|
|---|
Screw filter-presses
| - low rinsing water flow (regular flushing is not required);
- minimal noise background and vibration (high-strength base is not required);
- absence of odors and evaporations at workshop.
| - maintenance complexity (regular screw and perforated cylinder cleaning);
- lack of visual process operation control (only inspection holes are available);
- high sensitivity to initial sludge characteristics and concentration changes;
- high level of shell wearability, necessity of bearings replacement;
- restoration is available only within plant conditions;
- filtrate bad quality.
|
| Centrifuges | - devices portability;
- availability of nonchemical operation mode applying flocculants;
- high performance;
- odor absence;
- minimal rinsing water flow.
| - necessity of large inclusions and sand being extracted from sludge;
- necessity of periodical welding or screws changing;
- high power consumption.
|
Belt filter-presses
| - absence of wearing part and units;
- low power consumption;
- high equipment unit performance;
- • low suspended solids concentration in filtrate (in case of being returned to the “head” WWTP filtrate won’t affect adversely wastewater treatment processes);
- availability of mechanical dehydration process visual inspection;
- wide range of permissible input concentration.
| - higher dimensions and mass rate as compared with centrifuges;
- odor occurrence possibility;
- significant water flow for continuous filter belts flushing.
|
| Chamber filter-presses | - high dehydration rate;
- fine filtrate.
| - huge dimensions and mass;
- complicated foundation and sludge discharging unit design;
- low specific capacity (from the surface unit);
- enhanced chemical agents consumption;
- periodic activity.
|
