How to Choose a Mechanical Bar Screen

Solid Liquid Separator August 12, 2024 Trommel Screen

1. How to Choose a Mechanical Bar Screen？

The bar screen should be installed before the wastewater treatment system or pump.

Wastewater often contains various debris like fibers, wood, plastics, and paper of different sizes. To prevent damage or blockages in pumps, mechanical equipment, and pipes, and to ensure that subsequent treatment processes run smoothly, a bar screen should be placed before the wastewater treatment system or pump.

New wastewater treatment plants typically use one or two stages of coarse and medium bar screens, and sometimes even a third stage with fine bar screens.

2. Bar Screen Spacing

The gap width between the bars should meet the following requirements:

1. Coarse Bar Screen: When mechanically cleaned, the gap should be 16-25mm; when manually cleaned, it should be 25-40mm. In special cases, the maximum gap can be 100mm.
2. Fine Bar Screen: The gap should be between 1.5-10mm.
3. Ultra-Fine Bar Screen: The gap should not exceed 1mm.
4. Before the Pump: The gap width should be determined according to the pump's requirements (a bar screen must be installed before the pump).

In processes like membrane treatment and aerated biological filter systems, it's crucial to safely and effectively remove small particles like hair and fine fibers to prevent clogging of membrane modules or filter media, which could disrupt normal operations. Therefore, an ultra-fine bar screen is usually needed as a pre-treatment step before these processes. Based on practical experience from domestic and international projects, the gap width for ultra-fine bar screens should be less than or equal to 1mm.