The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 05, 1989
Filed:
Jun. 21, 1988
Toivo Niskanen, Hamina, FI;
A. Ahlstrom Corporation, Noormarkku, FI;
Abstract
A method and an apparatus for treating high-consistency fiber suspension are especially suitable for short distance conveyances of thick fiber suspensions (consistency more than 15%) in pulp and paper industry, for example for discharge of mass towers either with or without any actual pump. The treatment of fiber suspension with a consistency more than 15% is not possible with the known technique without a displacement type of pump, which is expensive and easy to break. Additionally, in discharging of the mass tower, drop leg, etc., fiber suspension causes trouble by arching in the container in such a way that it forms an open chamber around the pump located at the bottom of the container which chamber is slowly filled by fiber suspension. The problems are solved or minimized by arranging a feed apparatus (31) in the pump chamber, which feeds fiber suspension to a fluidizing rotor (21), for fluidizing the fiber suspension, whereafter the suspension flows onwards. The feeder apparatus raises the pressure of the fiber suspension sufficiently for the fluidization, not too high, in which case the operational members would be stressed redundantly. Fiber suspension is fed excessively to the rotor (21), whereby the feeding pressure of fiber suspension is controlled by throttling devices (34) arranged separate from the feeder apparatus in the back-circulation or passage.