KARMAN'S VORTEX FLOW METER

• Main Authors: MIZUNO TORU, SAWADA YUKIO, NANBA SHINJI, KOIKE OSAMU, MATSUI KAZUMA
• Format: Patent
• Language: English
• Published: 12.06.1987
• Subjects: MEASURING; MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUIDLEVEL; METERING BY VOLUME; PHYSICS; TESTING

PURPOSE:To reduce HF noise and improve an S/N ratio, by forming both side walls of a flow path into a curved surface with the shortest opposing distance in the middle of the path and installing a detecting sensor at the narrowest throat of the path. CONSTITUTION:A columnar vortex-generating part 1 is installed in a detecting part of a flow meter crosswise in the path at an angle of 90 deg. as shown by an arrow. The vortex- generating part 1 is composed of upstream-side half-piece 11 and downstream-side one 12 separated by a constant distance one from the other and the half-piece 11 is provided with the semi-circular front surface 111 facing the upstream side and the half-piece 12 is made of a rough T-cross-sectional form and the front end part 122 has roughly the same width as the half-piece 11 facing the same and it has a rear half-piece 123 extending to the downstream in step-wise narrowing widths as compared with the front part 122, and on the rear surface 121 of the rear half-piece 123 a guard plate 13 is attached and it runs parallel to the rear surface 121 in a fixed manner by legs 131, thus forming the flow path P between these parts concerned. The Karman's vortex V generated by the vortex-generating part 1 winds into the rear surface of the part 1, allowing the main component of the vortex oriented to the flow direction at an angle of 90 deg. to flow into the path P effectively for improvement of the S/N ratio of an output signal obtained from the detecting element 2.