How much can your vibratory screener process per hour? The answer depends on your material's bulk density, the mesh size you're running, the screener's effective screen area, and several operational factors that can significantly increase or decrease performance. The Throughput Estimator calculates an estimated capacity based on your inputs and provides a reference range based on ScreenerKing's application database.
Use the interactive estimator below for a quick calculation, then review the reference tables and methodology explanation on this page to understand how the estimate is derived and what factors might cause your actual performance to differ from the estimate.
How Is Vibratory Screener Throughput Calculated?
Screener throughput estimation uses an empirical specific capacity factor — expressed in kilograms per square meter of screen area per hour (kg/m²/hr) — combined with the effective screen area of your screener to estimate total capacity. The specific capacity factor varies by material type, bulk density, mesh size, and moisture content, and is derived from actual test data on thousands of applications.
The Basic Throughput Formula
The standard throughput formula for a round vibratory separator is:
Estimated Capacity (kg/hr) = Screen Area (m²) × Specific Capacity Factor (kg/m²/hr) × Correction Factors
Where the correction factors account for:
- Mesh size factor: Fine mesh reduces open area and reduces throughput. A 40 mesh screen has approximately 40% of the open area of a 20 mesh screen.
- Fines content factor: Materials with greater than 30% near-size particles (particles within ±25% of the mesh opening) require longer residence time, reducing throughput to 60 to 80% of the base estimate.
- Moisture factor: Materials with 2 to 5% moisture typically perform at 70 to 90% of dry throughput. Materials with greater than 5% moisture may require wet screening instead.
- Deck configuration factor: Multi-deck configurations run at 75 to 90% of single-deck capacity per deck.
Bulk Density Reference Table: 30 Common Materials
Bulk density is the weight of material per unit of volume, including the voids between particles. It is the most important material-specific variable in throughput estimation. Use this table to find your material's typical bulk density range for use in the estimator.
| Material | Bulk Density (kg/m³) | Bulk Density (lb/ft³) | Notes |
|---|---|---|---|
| Activated carbon (powder) | 200–350 | 12–22 | Wide variation by particle form |
| Alumina powder | 800–1,050 | 50–65 | Calcined grade; varies by mesh |
| Calcium carbonate (fine) | 700–1,100 | 44–69 | Increases with particle size |
| Cannabis trim (dry) | 100–200 | 6–12 | Very low density; screen slowly |
| Carbon black | 100–400 | 6–25 | Highly variable; prone to dusting |
| Cocoa powder | 480–640 | 30–40 | Hygroscopic; handle in low humidity |
| Coffee grounds | 300–450 | 19–28 | Varies by grind size |
| Corn starch | 550–700 | 34–44 | Hygroscopic powder |
| Diatomaceous earth | 150–350 | 9–22 | Low bulk density; fragile particles |
| Flour (wheat, all-purpose) | 450–600 | 28–37 | Aerates during screening |
| Graphite powder | 400–800 | 25–50 | Natural vs. synthetic varies significantly |
| Iron ore fines | 1,600–2,100 | 100–131 | High bulk density; high throughput |
| Iron powder (reduced) | 1,800–2,500 | 112–156 | Very high bulk density |
| Kaolin clay | 700–1,100 | 44–69 | Cohesive at high humidity |
| Limestone (crushed) | 1,200–1,600 | 75–100 | Varies with particle size |
| Magnesium citrate (powder) | 400–700 | 25–44 | Hygroscopic; process below 40% RH |
| Nylon pellets | 600–800 | 37–50 | Static management required |
| Polypropylene pellets | 500–700 | 31–44 | Standard injection molding grade |
| Salt (table, fine) | 1,100–1,400 | 69–87 | Corrosive; 316 SS required |
| Sand (dry, fine) | 1,400–1,600 | 87–100 | Free-flowing; high throughput |
| Silicon carbide powder | 1,000–1,500 | 62–94 | Highly abrasive; wears mesh quickly |
| Soda ash (light) | 400–600 | 25–37 | Caustic; 316 SS recommended |
| Sodium bicarbonate | 800–1,000 | 50–62 | Fine powder; may blind fine mesh |
| Sugar (granulated) | 750–900 | 47–56 | Hygroscopic; combustible dust |
| Talc powder | 700–1,000 | 44–62 | Low hardness; does not wear mesh |
| Titanium dioxide | 700–1,200 | 44–75 | Very fine particle; ultrasonic often needed |
| Turmeric powder | 500–700 | 31–44 | Color contamination risk; dedicated screens |
| Urea (granular) | 700–850 | 44–53 | Fertilizer grade; hygroscopic |
| Vitamin C (ascorbic acid) | 600–900 | 37–56 | Mildly hygroscopic crystals |
| Zinc oxide powder | 400–700 | 25–44 | Fine powder; requires dust containment |
Screener Diameter vs. Capacity Reference Table
This table shows the approximate throughput range for each ScreenerKing screener diameter at 20 mesh (841 micron), 40 mesh (400 micron), and 100 mesh (149 micron) for a typical free-flowing dry powder with bulk density of 600 kg/m³. These are reference estimates for preliminary sizing only — actual throughput depends on your specific material, mesh size, and operating conditions.
| Model | Diameter | Screen Area | 20 Mesh (841 µm) kg/hr | 40 Mesh (400 µm) kg/hr | 100 Mesh (149 µm) kg/hr |
|---|---|---|---|---|---|
| SiftPro 18" | 18" / 0.46 m | 0.16 m² | 200–400 | 100–200 | 30–80 |
| SiftPro 24" | 24" / 0.61 m | 0.29 m² | 350–700 | 175–350 | 55–145 |
| SiftPro 30" | 30" / 0.76 m | 0.44 m² | 550–1,100 | 275–550 | 85–220 |
| SiftPro 48 | 48" / 1.22 m | 1.16 m² | 1,450–2,900 | 725–1,450 | 225–580 |
| SiftPro 60 | 60" / 1.52 m | 1.81 m² | 2,250–4,500 | 1,125–2,250 | 350–900 |
Key Factors That Affect Screener Throughput
Particle Size Distribution (PSD)
Materials with a wide particle size distribution — where a significant fraction of particles is near the mesh opening size — screen more slowly than materials with a narrow, well-separated distribution. Near-size particles (within ±25% of the mesh opening) must contact the screen surface multiple times before they pass or are transported to the discharge, reducing effective throughput. For materials with greater than 30% near-size content, apply a 0.6 to 0.8 throughput correction factor.
Moisture Content
Moisture significantly reduces throughput by causing particle agglomeration and screen blinding. Even 1 to 2% surface moisture on a powder that normally runs at 0.5% moisture can reduce throughput by 30 to 50%. For moisture-sensitive materials, always measure and control incoming feed moisture. If moisture cannot be controlled, wet screening or heated-air screening may be required to maintain throughput.
Deck Configuration
Each additional deck in a multi-deck screener reduces the throughput per deck. The first deck processes 100% of the feed. The second deck processes whatever passes the first deck, which is typically 40 to 80% of the original feed volume. However, the second deck also has the same residence time and screen area as the first, creating a mismatch that reduces overall efficiency. Plan for 10 to 20% throughput reduction per additional deck when estimating multi-deck screener capacity.
Frequently Asked Questions: Screener Throughput
How do you calculate vibratory screener throughput?
Throughput = Screen Area (m²) × Specific Capacity Factor (kg/m²/hr) × Correction Factors for mesh size, fines content, moisture, and deck configuration. The specific capacity factor ranges from 200 to 1,500+ kg/m²/hr depending on material and mesh. Use the estimator tool above for application-specific calculations.
How does bulk density affect screener throughput?
Higher bulk density materials deliver more mass per unit of screen area per unit time at the same volumetric flow rate. A material at 1,200 kg/m³ delivers twice the throughput in kg/hr of a material at 600 kg/m³ on the same screener at the same mesh size. Always use the actual measured bulk density of your material — not a generic estimate — for throughput calculations.
What factors reduce screener throughput below the estimated value?
High fines content (near-size particles), moisture above 2 to 3%, fine mesh (below 60 mesh), multi-deck configuration, and surging feed systems all reduce actual throughput below estimates. Apply correction factors: 0.6 to 0.8 for high fines, 0.5 to 0.9 for moisture, 0.3 to 0.6 for very fine mesh, and 0.75 to 0.90 per additional deck.
How do I size a screener for a 5-ton-per-hour application?
Estimate required screen area: 5,000 kg/hr ÷ specific capacity factor × safety factor (1.25). For free-flowing mineral at 20 mesh with specific capacity of 800 kg/m²/hr: 5,000 ÷ 800 × 1.25 = 7.8 m² required. Multiple SiftPro 60 screeners (1.81 m² each) in parallel is the ScreenerKing solution for this scale. Contact ScreenerKing for application-specific sizing.
Does adding more screen decks increase or decrease throughput?
Adding decks reduces throughput per deck by 10 to 25% compared to a single-deck configuration of the same diameter, because additional mass reduces vibration amplitude at lower decks and each deck has the same residence time constraint regardless of how much material it receives. For maximum throughput, use multiple single-deck screeners in parallel rather than one multi-deck unit. Use multi-deck configurations when simultaneous multi-fraction separation is needed.