Thickening - Screw Press
Very high consistencies are required for low or high speed dispersion or for special storage and baling. The Kadant screw press design can reach up to 42% consistency.
Working principle
Stock at medium consistency is introduced into the screw and forwarded by the screw.
A basket with holes, mounted around the screw, retains the fiber mat whereas most of the water is evacuated through the holes. A pneumatically actuated flap creates a counter pressure resulting in the required stock plug which is needed to obtain significant de-watering of the stock.
Most screws are powered by a hydraulic motor which gives the highest flexibility and reduces the mechanical stresses.The screw operation is automatically adjusted in order to obtain the required consistency.
Applications
- Dispersion (low and high speed)
- High consistency refining
- Feeding of certain wet baling machines for lengthy storage purposes or for transport of the stock to other mills
- Feeding of big bags for the same purpose
Benefits
- Screw presses are the cheapest for maintenance
- Screw presses have the highest runnability
- Robust construction
- High consistencies
- Flexible and easy to control operating parameters