Belt Press Solids Capture Calculator
Capture percent is the report card for any dewatering unit. Enter feed and cake measurements to score capture, close the mass balance, and check filtrate quality.
Solids Capture
| Item | Value |
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How the calculation works
Formulas
Feed dry solids (lb/day) = flow (gal/day) × 8.34 × TS% ÷ 100
Cake dry solids (lb/day) = wet tons/day × 2000 × cake solids% ÷ 100
Capture (%) = cake dry solids ÷ feed dry solids × 100
Filtrate dry solids (lb/day) = feed dry solids − cake dry solids
Filtrate TSS (mg/L) = filtrate dry solids × 106 ÷ (filtrate flow (gal/day) × 8.34)
Feed dry solids (lb/day) = flow (gal/day) × 8.34 × TS% ÷ 100
Cake dry solids (lb/day) = wet tons/day × 2000 × cake solids% ÷ 100
Capture (%) = cake dry solids ÷ feed dry solids × 100
Filtrate dry solids (lb/day) = feed dry solids − cake dry solids
Filtrate TSS (mg/L) = filtrate dry solids × 106 ÷ (filtrate flow (gal/day) × 8.34)
Notes & limitations
Capture is a straight mass balance — no empirical factors. Well-run belt presses typically achieve 90–98% capture; screw presses and centrifuges run similar or better. Numbers outside that band usually point at bad measurements, not miracle performance.
- Capture above ~99% is suspicious — re-check the cake scale, the feed flow meter, and whether the lab %TS samples represent the same period.
- Capture below ~90% means real losses: polymer dose, belt tracking and tension, wash-water pressure, and feed consistency are the usual suspects.
- Feed and cake data must cover the same time window, or the balance will not close. Composite samples beat grabs for both.
- This tool works for any mechanical dewatering unit, not just belt presses — the math is the same.
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