Patent ID: 7141143

Claim:
A method of draining a fiber pulp suspension in a converging dewatering space defined between a first wire and a second wire each traveling from a pulp feed end toward a discharge end of the dewatering space, the dewatering space being configured such that water and a powdery substance are removed from the fiber pulp suspension through the first and second wires conveying the fiber pulp suspension along the dewatering space, the first and second wires having first and second pressure pulse elements, respectively, disposed adjacent thereto opposite the corresponding wire from the dewatering space, said method comprising: generating a positive pressure pulse directed toward the denaturing space with a positive pressure pulse portion of one of the first and second pressure pulse elements; and generating a negative pressure pulse in coincidence with the positive pressure pulse along the dewatering space, the negative pressure pulse being directed away from the dewatering space and being generated with a negative pressure pulse portion of the other of the first and second pressure pulse elements, such that the negative pressure pulse constructively interferes with and amplifies the positive pressure pulse through the dewatering space.