Light Material Separator

Why Light Material Separation Matters

Construction and demolition waste contains more than concrete blocks. It also includes sand and stone, timber offcuts, paper scrap and plastic bags. Concrete blocks can be reused as roadbed material, and the light fractions have their own uses as well. Treating all of this waste as a single stream not only wastes recoverable resources, it also allows the fractions to interfere with one another and degrade the quality of the end product. The light material separator is designed to remove timber, paper scrap, waste plastics and similar light fractions from construction waste.

Working Principle

The light material separator consists of a frame, an air duct, an air separation box and a centrifugal fan. The air separation box is fixed to the frame and has a material inlet, a heavy material outlet and a light material outlet. Inside the box is an inclined discharge surface whose upper end sits at the material inlet and whose lower end connects to the heavy material outlet, with a blower unit mounted behind it. In operation, material enters the box through the inlet and slides down the inclined surface under gravity. As it reaches the heavy material outlet, the blower drives the light fraction into the light material chamber for collection and further processing, while the heavy fraction discharges through the heavy material outlet.

Design Features

1. The inclined discharge surface inside the air separation box, together with the spreader plates fitted to it, slows the material as it slides and reduces bed depth — both of which help the light fraction separate more completely.
2. A backflow prevention plate opposite the discharge surface stops blown light material from escaping back through the feed hopper, while also cushioning incoming material.
3. A vertical partition between the heavy and light material outlets divides the box into a heavy material chamber and a light material chamber, preventing separated light material from returning and remixing with the heavy fraction. The ventilation window in the partition faces the blower outlet, which both raises separation efficiency and blocks light material from drifting into the heavy material chamber.
4. The fan sits behind the discharge surface with its outlet connected directly to the blower unit. This short path reduces air resistance and improves separation efficiency. The fan inlet is connected by duct to the top of the light material chamber, lowering the air pressure inside so that light material falls more readily under gravity.

Applications and Advantages

1. Suitable for separating timber offcuts, paper scrap, plastic bags and other light fractions in construction waste production lines.
2. The only drive component is a single 3 kW centrifugal fan, keeping running costs and power consumption low.
3. Simple construction and light weight reduce both manufacturing cost and the maintenance workload for operators.

Technical Specifications