The role of back flow in an axially fed pressure screen

Pressure screens have traditionally been fed tangentially to the periphery of the feed chamber. However, during the 1990s, axially fed pressure screen s have become more common because of their high energy efficiency. An axial ly fed pressure screen operates like centrifugal pump, which means there is a higher pressure in the accept and reject chambers than in the feed chamb er A tangentially fed pressure screen requires a feed chamber, but in the a xially fed version a feed chamber is not a structural necessity. A pressure screen without a feed chamber would save space and manufacturing costs. Ho wever, the present study showed that a pressure screen without a feed chamb er is not a viable option. The feed chamber plays an important role in the proper functioning of a pressure screen; it is in the chamber that pulp is accelerated to its full tangential velocity before the screen plate, The us e of too short a feed chamber or no feed chamber at all would reduce the ca pacity of axially fed pressure screen because the tangential velocity at th e front end of the screen basket would be insufficient, the result being bl ockage of the screen apertures.