Why Upfront Price Isn't the Full Story
Sludge dewatering equipment is often selected on quoted machine price alone — but power consumption, manpower requirements, consumables, and disposal costs (driven by cake dryness) compound over years of operation. Here's a fuller total cost of ownership picture across the three most common technologies.
Screw Press
- Upfront cost: Moderate
- Power consumption: Low — runs continuously at low RPM, typically 60–80% less power than an equivalent centrifuge
- Manpower: Low — largely automated, minimal operator attention needed
- Cake dryness: 18–25% dry solids
- Best for: Continuous-duty biological (STP) sludge, facilities prioritizing low running cost
Centrifuge (Decanter)
- Upfront cost: Highest of the three
- Power consumption: High — high-speed rotating bowl draws significant motor power
- Manpower: Low, but requires skilled maintenance technicians for the precision rotating assembly
- Cake dryness: 20–30% dry solids, generally the highest throughput of the three for large volumes
- Best for: Very large facilities where high throughput justifies the higher capital and running cost
Filter Press
- Upfront cost: Lowest to moderate, depending on plate count
- Power consumption: Low, but batch operation means higher per-cycle labour
- Manpower: Highest — batch cycle requires manual plate opening, cake removal, and cloth cleaning
- Cake dryness: 30–40% dry solids, generally the driest cake of the three — valuable when disposal cost is charged by wet weight
- Best for: Chemical/industrial sludge, facilities where maximum cake dryness reduces disposal costs enough to offset higher labour
5-Year TCO Comparison (Illustrative)
| Factor | Screw Press | Centrifuge | Filter Press |
|---|---|---|---|
| Capital cost | Moderate | High | Low-Moderate |
| 5-yr power cost | Low | High | Low |
| 5-yr labour cost | Low | Moderate | High |
| Disposal cost impact | Moderate | Moderate | Lowest (driest cake) |
Actual figures depend heavily on sludge characteristics, local power tariffs, and labour costs at your specific site — use this as a directional guide, not a final calculation.
QuaSys Inc. supplies screw press machines across India and can help calculate the TCO comparison specific to your sludge type and site conditions. Contact us for a comparison quote, or call +91 95408 15659.
