Some images are technical illustrations. Real installation photographs where marked.
Overview
The CG Mechanical Bar Screen™ is an automated inlet works screening system that removes coarse solid material from raw wastewater before primary treatment, protecting all downstream equipment — pumps, DAF/SAF nozzles, membrane modules, and aeration diffusers — from damage and clogging by rags, plastic, grit, and organic debris. The system uses a robust motorised rake mechanism that continuously or intermittently sweeps accumulated screenings from the bar rack and discharges them into a collection bin or compactor. Available in coarse (>20 mm), medium (6–20 mm), and fine (<6 mm) bar spacing configurations, and in inclined, vertical, and step-screen formats for any inlet channel geometry.
Working Principle
Raw wastewater flows through the inclined or vertical bar rack. Solid material larger than the bar spacing accumulates on the upstream face. The rake mechanism — driven by a chain-and-sprocket or rack-and-pinion drive — moves upward along the bar rack at programmed intervals, collecting accumulated screenings on its tines. At the top of travel, the rake passes over a cleaning brush or doctor blade that strips screenings into a collection hopper or conveyor chute. The cleaned rake returns to the base position and the cycle repeats. Cycle frequency is controlled by a timer or differential water level sensor — when headloss across the screen exceeds a set threshold, the rake activates.
Key Technical Features
- Bar spacings: 3–6 mm (fine), 6–20 mm (medium), 20–50 mm (coarse)
- Chain-and-sprocket or rack-and-pinion rake drive
- Inclined (70–80°) or vertical channel mounting
- Timer or differential level sensor cycle control
- SS304 (standard) or SS316 (marine/aggressive) wetted parts
- Self-cleaning rake tines with doctor blade or rotating brush
- Variable speed drive option
- Suitable for channel widths 300–2,000 mm
- Suitable for channel depths 500–3,000 mm
- IP65 or IP68 motor and electrical enclosure
Design Parameters
| Parameter | Value |
|---|---|
| Bar Spacing | 3–50 mm |
| Channel Width | 300–2,000 mm |
| Channel Depth | 500–3,000 mm |
| Drive | Chain/Sprocket or Rack & Pinion |
| Material | SS304/SS316 |
| Control | Timer/Diff. Level |
| Protection | IP65/IP68 |
Applications
- Municipal STP inlet works
- Industrial ETP inlet works — food, textile, pharmaceutical
- Slaughterhouse and meat plant effluent inlet screening
- Combined sewer overflow (CSO) screening
- Pumping station inlet protection
- River intake screening for water treatment plants
Advantages
- Protects all downstream equipment — reduces pump and nozzle maintenance
- Automated operation — no manual rake cleaning required
- Stainless steel for long corrosion-free service life
- Variable bar spacing for all wastewater types
- Differential level control ensures screen always clear — no flooding risk
- Suitable for compact or existing channel dimensions
Frequently Asked Questions
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