Wedge Wire Screen Drum

A wedge wire screen drum – also known as a pressure screen drum or screen cylinder – is a cylindrical screening component manufactured from V-shaped stainless steel profile wires resistance-welded to a grid of support rods. The drum is installed inside a pressure screen housing, where it operates under positive pressure to screen pulp slurries, mineral slurries, or other liquid-solid suspensions. The drum rotates or remains stationary depending on the screen design, with the slurry flowing through the wedge wire slots to separate acceptable fibers or particles from rejects. The all-welded construction provides high mechanical strength, enabling the drum to withstand differential pressure without deforming.

The V-shaped slot geometry ensures consistent screening performance. The slots are narrow at the outside surface and wider internally, which prevents particles from becoming wedged and blocking the flow. This design maintains high screening efficiency over long operating periods. Slot openings range from 0.08 mm to 1.0 mm, with common applications using 0.1 to 0.35 mm for fine screening. Slot tolerance is held to ±0.02 to ±0.04 mm, ensuring that every slot across the drum surface provides the same screening accuracy. The open area typically ranges from 25% to 45%, providing good throughput while maintaining separation precision.

The screen drum is constructed with profile wires on the outside surface and a grid of support rods on the inside. The profile wires and support rods are welded at every intersection. For high-pressure applications, support rods are spaced more closely, and additional circumferential stiffener rings are added to prevent the drum from collapsing under pressure. Profile wire sizes commonly used include 1×2 mm, 1.5×3 mm, and 2×4 mm. The drum can be manufactured with or without a flange at each end, depending on the pressure screen design. Materials include stainless steel 304 and 316L, with 2205 duplex steel available for more demanding applications.