A mechanical bar screen is a type of screening device capable of automatically removing debris that adheres to the screen.

The mechanical bar screen is one of the early purification devices in water supply and drainage treatment technology. It significantly reduces the labor intensity of workers, protects their health, lowers the head loss of incoming water, and improves the efficiency of pumping stations.

Composition

The rotary bar screen consists of a motor reduction device, plow-shaped rake teeth, a debris brush, and other components.

Working Principle

It is composed of many identical rake tooth components assembled alternately and parallel to form a closed rake tooth chain. Driven by a motor and a reducer, it performs a continuous top-to-bottom cyclic motion through a set of pulleys and chains, achieving continuous screening. When the rake tooth chain operates to the upper and back parts of the device, the guidance of the sprocket and curved track causes the parallel rake teeth to dislocate, allowing solid debris to fall into the residue tank by gravity. If the debris is not completely removed, such screens may carry the debris into the channel behind the screen.

During the operation of the wire rope-driven drum mechanical bar screen, the wire rope driving device releases the rope, and the rake bucket moves downward along the guide rail from the highest position (where the previous skimming cycle ended). The skimming plate descends with the rake bucket under its own weight. After the skimming plate resets, the rake bucket opens under the push of the rake opening/closing device (electric push rod) and continues to descend until it reaches the lower limit of the channel. Once the rake teeth insert into the screen gaps, the wire rope driving device retracts the rope, forcing the rake bucket to close completely. The rake bucket and the trolley then move upward along the guide rail. The screened debris touches the skimming plate, and through their relative motion, the debris is skimmed off and falls into the residue tank via the guide plate, completing one working cycle.

Performance Advantages

The greatest advantages of the rotary mechanical bar screen are its high degree of automation, high separation efficiency, low power consumption, no noise, and excellent corrosion resistance. It can operate continuously and stably without supervision and is equipped with an overload safety protection device that automatically stops the machine in case of malfunction, preventing overload operation.

The device can be adjusted arbitrarily according to user needs for operational intervals, enabling periodic operation. It can also be automatically controlled based on the liquid level difference before and after the screen and has a manual control function for convenient maintenance. Users can choose according to their specific work requirements. Due to its rational structural design, the device has strong self-cleaning capabilities during operation, preventing clogging, which minimizes daily maintenance工作量.

Function

The rotary mechanical bar screen can effectively separate solid materials, reduce suspended solids (SS) and chemical oxygen demand (COD) in water, and alleviate the processing load of subsequent procedures. It is also used in industrial production for solid-liquid separation and the recovery of useful materials.

Scope of Application

Used in industrial wastewater treatment for papermaking, slaughtering, leather, sugar refining, brewing, food processing, textiles, printing, dyeing, petrochemicals, etc., to remove suspended solids, floating materials, sediments, and other solid substances;

Used in industries such as papermaking, alcohol, starch, and food processing to recover useful materials like fibers and residues;

Used in urban sewage treatment to replace primary sedimentation tanks.