Automatic Screen

Automatic screen is a mechanical equipment used in the initial stage of wastewater treatment (pretreatment) to automatically filter coarse solids from the wastewater stream before entering the next process such as grit chamber or sedimentation. The following is a complete explanation:

Automatic Screen Function

1. Filters out coarse solids

   • Removes solids such as plastic, cloth, logs, paper, and other large debris that can clog pipes or damage pumps and downstream equipment.

2. Protects subsequent process equipment

   • By reducing the solids load, the efficiency of the next unit increases and the risk of mechanical damage decreases.

3. Reduces maintenance costs

   • As blockages and equipment damage are reduced, maintenance frequency becomes less frequent.

Working Principle of Automatic Screen

Automatic screens work automatically using a motor and rake system to lift and remove solid material from wastewater.
Stages:

1. Wastewater flows through a bar screen (arrangement of metal rods).

2. Coarse solids are retained on the surface of the screen.

3. A mechanical rake system moves periodically (or based on water level sensors) to lift the solids up.

4. The lifted solids are then discharged to a conveyor or holding container for dewatering or disposal.

Advantages of Using Automatic Screen

• Automatic and continuous operation, no manual cleaning required.

• High efficiency in removing solids.

• Large capacity and suitable for modern installations.

• Can be equipped with a water level sensor to adjust the cleaning frequency.

Applications

Automatic screen is widely used in:

• Domestic wastewater treatment plants (WWTP).

• Food and beverage industry.

• Chemical, textile and pharmaceutical industries.

• Municipal wastewater treatment plant.