The rotary mechanical screen is a solid-liquid separation device widely employed in the pre-treatment stage of wastewater processing. Its core feature lies in achieving continuous, automated interception and removal of impurities. Understanding its operational principles and function is crucial for optimising the stability and efficiency of the entire water treatment system.

   I. How does a rotary mechanical screen operate?
The operation of a rotary mechanical screen relies on a precision mechanical transmission system, primarily involving the following steps:

Interception Stage: Installed at an angle within the channel, the screen intercepts solid debris larger than the bar spacing (such as plastic items, branches, fibrous materials, etc.) as wastewater flows through, trapping it outside the screen.

Lifting Stage: Driven by an electric motor reducer, the rake chain performs continuous rotational movement, ‘scooping up’ the intercepted debris from the bottom of the screen and lifting it upwards along the chain.

Discharge and Cleaning Stage: Upon reaching the top drive unit, the rake chain reverses direction via guide wheels. Debris is then dislodged by gravity or counter-rotating cleaning brushes, falling into a collection trough or conveyor for automatic discharge.

Cyclic Operation: The cleaned rake chain continues its downward rotation, re-entering the water body to commence a new operational cycle, thereby establishing an uninterrupted cleaning process.

   This sequence achieves effective separation of debris from water while ensuring sustained unobstructed flow through the channel.

   II. What Key Role Does It Play in Sewage Treatment Systems?
Within wastewater treatment processes, the rotary mechanical screen serves as the primary physical treatment unit, performing an irreplaceable function primarily manifested in two aspects:

Core protective function: It effectively removes larger solid debris from wastewater, preventing these impurities from entering subsequent process stages. This avoids issues such as pump impeller entanglement, pipeline blockages, and valve damage, significantly reducing the failure rate and maintenance costs of downstream equipment.

Enhanced Overall Efficiency: Through efficient pre-treatment, it establishes stable, clean water conditions for subsequent biochemical treatment, sedimentation, and filtration processes. This prevents impurities from interfering with microbial activity or causing sludge accumulation in treatment structures, thereby ensuring the efficient and stable operation of the entire wastewater treatment system.

   Selecting a stable-operating, high-efficiency screen is fundamental to the entire system's reliable performance. For markets like Germany and the United States, where equipment reliability demands are exceptionally stringent, a supplier's capability for independent R&D and comprehensive production lines are critical evaluation criteria.

   Take Jiangsu Longdai Environmental Protection Group Co., Ltd. as an example. We are a specialised manufacturer dedicated to the independent R&D and production of water treatment pre-treatment equipment. Our modern on-site factory and automated production lines enable precision machining and stringent quality control of core components (such as rake chains and transmission systems), ensuring every grating unit leaving our premises delivers outstanding mechanical performance and extended service life.

   Our rotary mechanical screen products have been successfully exported to 27 countries worldwide, including the United States, Russia, Germany, and Turkey, serving numerous municipal and industrial wastewater treatment projects. Their reliability and adaptability have been proven through long-term operation in diverse complex environments and operating conditions. Choosing Jiangsu Longdai means selecting a partner you can trust for quality, technology, and global service.