Druckbild

External rotor wing internal flow pressure screen is an advanced pulp separating which can not only be used for pulp separation of the pulping system but also be used for extraction of sizing agents before used in a paper machine. The pressure screen takes the pressure difference between the interior and exterior of the screen cylinder and the positive pressure on the head of the rotor wings as the screening power and utilizes the pulses of the pressure generated by the high speed gyration of the rotor wings to play a part in self-cleaning, then sizing agents not screened enter into the position between the screen cylinder and the cylinder body from the pulp inlet along the paper cutting direction; qualified fibers flow in the screen cylinder through screen openings (or cuts) and are expelled through the good pulp pipe; and the tailings left outside of the screen cylinder are expelled through the sullage pipe at the bottom with the propulsion of the pulp currents and the rotor wings. When the pressure screen is in operation, sizing agents flow from the outside of the screen cylinder to the inside of it; the rotor wings rotate on the outside of the screen cylinder; the sizing agents flow at the converse direction of the centrifugal force; impurities are removed at the same direction of the centrifugal force, thereby the pressure screen has the advantages of high slag removal efficiency, no blockage of the screen cylinder, and no generation of pulses due to that the sizing agents on the outlet are expelled from directly under the rotor wings. Compared with a traditional external flow pressure screen and an internal rotor wing internal flow screen, the external rotor wing internal flow pressure screen has the following advantages: 1 The sizing agents after screening are better in quality; 2 The screen cylinder is not easy to be blocked, thereby smaller dimensions of screen openings (cuts) can be adopted; 3 Strong treatment capacity and low consumption of relative power; 4 Low screening rate. Model