Dewatering centrifugal dryer (Spinner)

In plastic recycling, a centrifugal dryer is a machine that removes free surface water from washed plastic flake by spinning it at high speed inside a screen basket. It is also called a dehydrator, mechanical dryer, spinner or centrifuge machine. It runs at a stable 1,500 RPM and brings a plastic flake stream to a residual moisture content of under 1–8%, with throughput reaching 2,000 kg/h.

For washed flake in a recycling line, the centrifugal or mechanical dryer is the standard first stage, because it removes water with a motor rather than with fuel. Thermal drying still has a place, but it runs after the spinner rather than instead of it, handling the moisture that centrifugal force physically cannot reach.

A residual moisture content of under 1–8% on a plastic flake stream. The spread is material driven rather than machine driven: dense rigid regrind sheds water easily and sits at the low end, while thin film holds far more water per kilogram and sits at the high end. Adding an electrical heating box raises drying efficiency further.

A stable 1,500 RPM. On this machine consistency matters more than peak speed, because the rotor is continuously throwing wet and unevenly distributed flake against the screen basket. Steady operation at 1,500 RPM is what gives thorough and fast dewatering across a mixed stream.

Because film carries far more water per kilogram and gives it up more slowly, so it needs longer in the rotor. On the WTS-650 that is 500–1000 kg/h on rigid scrap against 300–400 kg/h on soft film; on the WTS-850, 1500–2000 kg/h against 500–600 kg/h. Size a film line from the film row, not the rigid row.

It depends on what the flake feeds. The spinner removes free surface water mechanically and cheaply; it cannot remove what centrifugal force does not reach. Material going to storage is usually fine as it leaves the dryer. Material going into an extruder normally needs a heated stage after it, because residual water flashes to steam in the melt.

The basket is modular and reached through an easy-access hatch, so cleaning and replacement are routine rather than a strip-down. Watch residual moisture as the early warning: fines and fibre gradually blind the perforations, and a blinded screen holds water in, so output gets wetter well before anything sounds or looks wrong.