Reducing the noise of pressure pulp screen
Keywords:
acoustic noise, noise abatement, structural acoustics, pressure pulp screen, paper pulp, noiseAbstract
A pressure pulp screen is a device able of classifying and separate fibers in paper pulp. The machine is made of two concentric cylinders closed at both extremities. The inner cylinder, called `basket' is perforated. The size and the form of holes is determined by the considerations on the quality of paper and the time where classification occurs during the process. The pulp is injected under pressure in the centre part of the machine. The accepted pulp goes through the holes of the basket and is collected by a pipe connected at the part between the two cylinders. Refused pulp is collected by an other pipe in the centre part of the machine. In order to clean the holes of the basket, the depression made by blades moving at less than 5 mm of the inner side of the basket is used. These blades are supported by a rotor running at 1150 rpm. The noise of this machine is characterised by a discrete spectrum in middle and high frequencies. Levels depends of the consistency of pulp (1 to 4% of fibers), the type of holes (vertical slots, profiled circular holes) and speed of rotation of the rotor. Classical sound power levels in industry are 95 dB(A) for a basket with circular holes for a diameter of 90"Additional Files
Published
How to Cite
Issue
Section
License
Author Licensing Addendum
This Licensing Addendum ("Addendum") is entered into between the undersigned Author(s) and Canadian Acoustics journal published by the Canadian Acoustical Association (hereinafter referred to as the "Publisher"). The Author(s) and the Publisher agree as follows:
-
Retained Rights: The Author(s) retain(s) the following rights:
- The right to reproduce, distribute, and publicly display the Work on the Author's personal website or the website of the Author's institution.
- The right to use the Work in the Author's teaching activities and presentations.
- The right to include the Work in a compilation for the Author's personal use, not for sale.
-
Grant of License: The Author(s) grant(s) to the Publisher a worldwide exclusive license to publish, reproduce, distribute, and display the Work in Canadian Acoustics and any other formats and media deemed appropriate by the Publisher.
-
Attribution: The Publisher agrees to include proper attribution to the Author(s) in all publications and reproductions of the Work.
-
No Conflict: This Addendum is intended to be in harmony with, and not in conflict with, the terms and conditions of the original agreement entered into between the Author(s) and the Publisher.
-
Copyright Clause: Copyright on articles is held by the Author(s). The corresponding Author has the right to grant on behalf of all Authors and does grant on behalf of all Authors, a worldwide exclusive license to the Publisher and its licensees in perpetuity, in all forms, formats, and media (whether known now or created in the future), including but not limited to the rights to publish, reproduce, distribute, display, store, translate, create adaptations, reprints, include within collections, and create summaries, extracts, and/or abstracts of the Contribution.