Rotary Bar Screens

Mojan Rotary Mechanical Bar Screens are designed for the continuous and automatic removal of coarse solids from wastewater streams. They can be installed in open channels and used as a preliminary treatment unit in municipal and industrial wastewater treatment plants across a wide range of flow rates.

The screening section consists of parallel rolled flat bars or round bars manufactured from stainless steel or structural steel, depending on the project requirements. A mechanical cleaning rake continuously removes the accumulated screenings from the screen surface, allowing wastewater to flow through the screen efficiently.

Main Components

The main components of Mojan Rotary Mechanical Bar Screens include:

Screening Grid

The screening grid consists of parallel flat bars or round bars manufactured from stainless steel or structural steel. The bar spacing is selected according to the required screening efficiency and characteristics of the wastewater.

Cleaning Rake

The cleaning rake is responsible for removing accumulated solids from the screening grid. During each cleaning cycle, the rake moves across the screen and transfers the collected screenings toward the discharge point.

Rake Cleaning Mechanism

A dedicated rake cleaning mechanism removes the collected screenings from the rake during each rotation and directs them to a screenings collection basket or conveyor belt for collection and disposal.

Geared Motor

An electric geared motor provides the required mechanical drive for the cleaning rake and enables continuous or demand-based operation of the screening system.

Torque Switch

A torque switch provides mechanical protection in the event of excessive resistance or blockage. If the screening mechanism encounters an abnormal load, the torque switch stops the rake movement to help protect the equipment from damage.

Main Frame

The main frame is manufactured from stainless steel or structural steel profiles and provides the structural support required for the screening grid, cleaning mechanism, and drive system.

Operating Mechanism

Mojan Rotary Mechanical Bar Screens are designed for fully automatic operation. The cleaning cycle can be controlled by a differential water level sensor, level switch, or timer, while manual operator control can also be provided when required.

During normal operation, wastewater flows through the screening grid while coarse solids are retained on the screen surface.

As screenings accumulate, the water level upstream of the screen gradually rises. When the water level reaches the preset operating point, the level switch activates the geared motor.

The geared motor rotates the cleaning rake, which moves across the screening grid and removes the accumulated solids. As the screen is cleaned, the hydraulic passage is restored and wastewater can flow through the screen with reduced obstruction.

The collected screenings are then discharged into a collection basket or onto a conveyor system for further handling and disposal.

Key Features

• Fully automatic operation
• Simple and robust design
• Compact configuration
• Efficient continuous screening
• Fast and straightforward installation
• Minimal civil works required for installation
• Simple operation and maintenance
• Automatic cleaning mechanism
• Differential level or timer-based control
• Manual operator control option
• Torque protection system
• Suitable for concrete channels
• Suitable for prefabricated steel channels
• Available in stainless steel or structural steel construction

Applications

Mojan Rotary Mechanical Bar Screens can be installed in open channels as a preliminary wastewater treatment unit and are suitable for:

• Municipal wastewater treatment plants
• Industrial wastewater treatment plants
• Wastewater pumping stations
• Preliminary treatment systems
• Coarse solids removal
• Protection of downstream pumps and treatment equipment
• Concrete and prefabricated steel channels
• Projects with different wastewater flow rates

Customized Design by Mojan

Mojan designs and manufactures Rotary Mechanical Bar Screens according to the specific hydraulic and operational requirements of each project.

The equipment can be customized based on:

• Design and peak wastewater flow
• Channel dimensions
• Required bar spacing
• Type and quantity of screenings
• Screen installation configuration
• Material of construction
• Cleaning cycle requirements
• Control method
• Screening collection and disposal system

This customized approach enables Mojan to provide reliable automatic screening solutions for a wide range of municipal and industrial wastewater treatment applications.