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:
Jan. 07, 1997
Filed:
Mar. 08, 1995
Harri Pitkanen, Espoo, FI;
Markku Simula, Vantaa, FI;
Neles-Jamesbury Oy, Helsinki, FI;
Abstract
A method and a device for reducing the noise caused by throttling a gas flow in a flow channel (1), where after the throttling part (2) there is a wider part (3). The wider part (3) following the throttling part (2) of the flow channel (1) has at least one deviation of the cross-section (D) formed by a wall protrusion (5) in a short part (1) of the channel. The cross-section of the channel wall protrusion (5) taken length-wise of the channel tapers towards the central part of the channel. In a trans- or supersonic flow the protrusion causes a straight shock wave, a so-called Mach disk, in the flow, and this disk is made to occur and to remain within a wide pressure drop ratio range.