Twin Classifier


Twin classifiers from Lackeby Products are designed to separate both settled and floating particles from water. The robust design underpins high reliability and a long technical service life, while maintenance requirements are minimal.


The flow is directed into the machine via the top-mounted inlet and slowed down by the back wall of the tank. During the period of flow through the machine, the solid material settles and the floating material rises to the surface. The screen-fitted outlet is located in the narrow section of the tank. Floating material is captured in the outlet’s screening plate and transported out via a shaftless spiral. The screening plate is continuously cleaned by a brush on the lower part of the spiral. For maximum dewatering, the settled material is transported out by a shaftless pulling spiral.


As standard, twin classifiers are manufactured in stainless steel (1.4301) or (1.4436) and with shaftless spirals in black material (S355J0). The lower part of the spiral is fitted with a nylon brush. Throughs are coated with Hardox wear bars or Robalon wear liners.

Technical features

Process benefits

• Robust and compact design • Separates both sedimentary and floating particles
• Simple installation • Screens outgoing liquid
• Shaftless screw conveyor for outfeed of dewatered material • Maximises dewatering
• Without bearing at the bottom end of the conveyors • Minimises maintenance
• Large sedimentation tank • Reduces energy consumption


Lackeby has over a hundred installations classifiers. Dubbelavvattnaren it has been installed at Metso Panelboard, Masisa, Chile.