Cleaning of used paper and cellulose suspensions uses an eddy chamber for the suspension where injected water flows at a high relative speed to separate particles and gels and break up fiber clumps

摘要

To detach particles and gels from suspended paper materials, and break up paper fiber clumps, the suspension (S) is subjected to a water (W) flow from a number of flow channels (1,1') with a high relative speed of at least 30 m/s, to give the particle separation and break-up action. The relative flow speed (V1) is at least 60 m/s. On entry into the system the suspension (S) is moved in a flow, with a speed component aligned against the water (W) emerging from the channels (1,1'). A flow channel (1') has a narrowed section, along part of its length, to accelerate the water (W) flow, in the form of a tapering conical jet. The smallest clear width of the water flow channel (1) is max. 10 mm. The suspension (S) is passed through an eddy chamber (2), where at least one water flow channel (1) opens into it. The flow vol. of the water (W) is at least 20% of the fiber suspension (S) flow vol. The water flow vol. through a flow channel (1) is max. 2 l/s. The suspension (S) has a solid content of = 6%, and is mostly of used paper.