US 5,200,072 A · Screen plates and methods of manufacture

Abstract

The screen cylinder includes a screening plate having contoured grooves along an inflow side and a backing cylinder having a plurality of openings therethrough and disposed on the outflow side of the screening cylinder. The contoured grooves are elongated in the axial direction and are closely circumferentially spaced one from the other about the screen cylinder. In one embodiment, circumferentially extending grooves are formed along the outflow side of the screening cylinder whereby pulp flows through the contoured grooves into the recesses and then through the openings of the backing cylinder. In another embodiment, the recesses are formed on the inflow side of the backing cylinder, the screening cylinder being provided with elongated slots along its outflow side in registry with the contoured slots. In this manner, increased flow capacity is provided. Additionally, the screening cylinder is removable when worn for replacement by a fresh screening cylinder which may then be secured to the backing cylinder.

Claims23

Dependent claims

A screen cylinder comprising:

a generally cylindrical screening medium having a plurality of openings therethrough;
a generally cylindrical structural backing plate for structurally supporting said screening medium and having a plurality of openings therethrough;
and
said screening medium and said structural backing plate lying concentrically one within the other and having respective opposed surfaces in engagement with one another at an interface therebetween whereby said backing plate structurally supports said screening medium;
one of said screening medium and said backing plate having a plurality of circumferentially extending recesses formed in its opposing surface and opening at the opposing surface of the other of said screening medium and said backing plate at the interface thereof establishing communication between the respective openings of said screening medium and said backing plate;
a plurality of axially spaced projections spaced one from the other in the axial direction defining said recesses and projecting radially from one of said screening medium and said backing plate at said interface;
the openings in said screening medium being elongated and extending in a generally axial direction substantially normal to the circumferential extent of said recesses.

4 more elements

A screen plate for screening pulp flowing therethrough comprising:

a screening medium having a plurality of slots therethrough and extending generally parallel to one another, said slots having contoured portions on an inflow side of said screening medium;
a structural backing plate having a plurality of openings therethrough;
said screening medium and said structural backing plate lying in registration one with the other and having respective opposed surfaces in engagement with one another at an interface therebetween whereby said backing plate structurally supports said screening medium;
one of said screening medium and said backing plate having a plurality of recesses formed in its opposing surface and opening at the opposite surface of the other of said screening medium and said backing plate at the interface thereof establishing communication between the openings of said backing plate and said slots of said screening medium;
whereby pulp may flow sequentially through said slots, said recesses and said openings in said backing plate.

2 more elements

Dependencies are inferred from the claim text.

Screen plates and methods of manufacture

Life of this patent

Screen plates and methods of manufacture

Life of this patent

Abstract

Claims23