Screening Plant
A screening plant separates crushed or excavated material into size fractions by passing it over vibrating screen decks — each deck's mesh retaining oversize and passing undersize. Screens are the sorting stations of every aggregate, topsoil and recycling operation, turning mixed feed into salable, specification products.
How it works
A feeder or conveyor delivers material onto an inclined or horizontal screen box carrying one to three decks of progressively finer media. Out-of-balance shafts or exciters vibrate the box so particles stratify — fines sink through the bed and pass the mesh, oversize travels down-deck and discharges over the end. Each fraction leaves on its own conveyor, building separate stockpiles from one feed. Scalping screens run heavy media (grizzly bars, punch plate) ahead of crushers to pull dirt and fines out of blasted or demolition feed; finishing screens run woven mesh behind crushers to cut final product sizes. Tracked mobile plants integrate feeder, screen box, engine and folding stockpile conveyors into one transportable machine — catalog records for the class run 15,400-38,000 kg with 130-225 hp engines.
Types & variants
- Scalping screens
- Heavy-media machines ahead of the crusher, removing fines and dirt from raw feed.
- Inclined finishing screens
- Multi-deck machines cutting final aggregate sizes behind crushers.
- Horizontal screens
- Low-headroom, high-accuracy machines favored in portable spreads.
- Tracked mobile screens
- Self-contained crawler plants with folding stockpile conveyors.
Key specifications
| Specification | Typical range | What it means |
|---|---|---|
| Operating weight | 34,000–83,800 lb (15,422–38,011 kg) | From catalog records of 15,400-38,000 kg for mobile plants — the transport-planning figure. |
| Engine power | 130-225 hp | From catalog records of 130.1-225.3 hp driving vibration, feeder and conveyors. |
| Deck configuration | Model-specific (commonly 2-3 decks) | Deck count sets how many products one pass produces; current catalog records do not carry banded deck dimensions. |
How the industry sizes it
Screening plants are sized by screen-box area and deck count against required throughput and the number of products to be made — more area passes more tonnage at a given cut accuracy. The catalog's mobile-class records run 15,400-38,000 kg and 130-225 hp; selection pairs the screen to the crusher or excavator feeding it, with scalpers matched to raw feed and finishing screens to final gradations.
Applications
- Sizing crushed stone into specification aggregate products
- Scalping dirt and fines from blasted rock and demolition feed
- Topsoil, sand and gravel screening in pits
- Recycled concrete and asphalt product separation
- Compost, biomass and waste-stream sizing in material yards
Safety & operation
- Lock out before entering the screen box or changing media — stored vibration energy and counterweights are lethal during maintenance.
- Guard all conveyor nips and transfer points; belts cause most screening-spread injuries.
- Control dust at feed, decks and discharge per respirable crystalline silica requirements.
- Set up level on competent ground — a vibrating machine walks and destabilizes on poor pads.
- Keep personnel off running equipment; no crossing the feed hopper or decks in operation.
Standards & certifications
- MSHA · 30 CFR Part 56
- Surface mine safety rules covering screening operations in pits and quarries.
- OSHA · 29 CFR 1926.1153
- Respirable crystalline silica requirements for construction material processing.
- OSHA · 29 CFR 1926.555
- Conveyor guarding and emergency-stop requirements.
- EPA · Tier 4 (40 CFR Part 1039)
- Emissions certification for mobile plant engines.
Frequently asked
What is the difference between scalping and finishing screens?
How many products can one screen make?
How big are mobile screening plants?
Compare popular models
Find by spec →Normalised to the same units. A dash means the figure was not published.
| Model | Operating weight | Max dig depth | Max reach | Engine power |
|---|---|---|---|---|
| McCloskey International R70 | 33,951 lb (15,400 kg) | - | - | 130 hp |
| McCloskey International R155 | 72,091 lb (32,700 kg) | - | - | 130 hp |
| McCloskey International R230 | 82,012 lb (37,200 kg) | - | - | 225 hp |
| McCloskey International S80 | 42,439 lb (19,250 kg) | - | - | 130 hp |
| McCloskey International S130 | 61,729 lb (28,000 kg) | - | - | 130 hp |
| McCloskey International S250 | 83,776 lb (38,000 kg) | - | - | 225 hp |
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Sources
Every specification is verified against the manufacturer's published data, with the source linked for reference.
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