Patent · US Expired

Paper stock screening apparatus having heavy rejects trap

US5186332A · kind A · utility

8Cited by
11References
12Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 14, 1991
Grant dateFeb 16, 1993
Priority date
Expiry dateJun 14, 2011

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB07B1/20
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

Screening apparatus for paper making stock comprises a generally cylindrical vertical housing having the interior thereof separated by a cylindrical perforated screening member into a screening chamber and an annular accepts chamber on the inner and outer sides of the screening cylinder respectively. The feed stock enters an inlet chamber below the screening chamber tangentially, and special provision is made for preventing heavy reject particles from circulating around the bottom of the inlet chamber. For this purpose, the inlet chamber is provided at a position spaced circumferentially downstream from the inlet port, with an outlet port into which high specific gravity particles are carried by centrifugal force along with the carrying liquid. A conduit leads from this outlet port back to the inlet chamber in order to maintain a continuous flow through this conduit. At an intermediate position along this conduit, provision is made for trapping heavy particles entrained with the stock passing through the conduit, and these trapped particles are purged from time to time.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.