Vortex shedding flow meter

Abstract

The present invention relates in general to vortex shedding flow meters with enhanced sensitivity for sensing and measuring vortex frequencies.

What is claimed is: 
     
         1 . A vortex shedding flow meter comprising:
 a. a housing;   b. a bluff body having a first side that makes initial contact with the flow of a fluid; and,   c. a detector wing positioned behind the bluff body in relation to the flow of fluid, the detector wing having a channel within the wing that extends; wherein the channel further includes:
 i. a Y-cut lithium niobate crystal to sense deflections of the detector wing; and 
 ii. a pair of electrodes that make contact to the Y-cut lithium niobate crystal and extend through the channel to the housing. 
   
     
     
         2 . The vortex shedding flow meter of  claim 1 , wherein the Y-cut lithium niobate crystal is positioned such that its Y-axis is perpendicular to the deflection of the detector wing. 
     
     
         3 . The vortex shedding flow meter of  claim 1 , wherein the vortex shedding flow meter further includes a shroud that surrounds at least a portion of the detector wing and the bluff body. 
     
     
         4 . The vortex shedding flow meter of  claim 3 , wherein the bluff body is oriented in a cantilever manner from the shroud. 
     
     
         5 . The vortex shedding flow meter of  claim 3 , wherein the electrodes are fused to the crystal with the use of silver or silver palladium. 
     
     
         6 . The vortex shedding flow meter of  claim 1 , wherein the vortex shedding flow meter includes a temperature sensor within the housing. 
     
     
         7 . The vortex shedding flow meter of  claim 7 , wherein the temperature sensor is a resistance temperature detector. 
     
     
         8 . The vortex shedding flow meter of  claim 1 , wherein the bluff body is oriented in a cantilever manner from the housing. 
     
     
         9 . The vortex shedding flow meter of  claim 1 , wherein the Y-cut crystal is oriented within at least two spacers that are fit within the channel of the detector wing. 
     
     
         10 . The vortex shedding flow meter of  claim 9 , wherein the spacers are constructed of ceramic material. 
     
     
         11 . The vortex shedding flow meter of  claim 1 , wherein a screw is utilized within the channel to maintain the position of the Y-cut lithium niobate crystal. 
     
     
         12 . A vortex shedding flow meter comprising:
 a. a shroud of generally tubular shape;   b. a housing connected to the shroud;   c. a bluff body oriented in a cantilever manner from the shroud and having a first side that makes initial contact with a flow of a fluid; and,   d. a detector wing oriented in a cantilever manner from the housing and positioned downstream the bluff body in relation to the flow of fluid, the detector wing having a channel within the wing, wherein the channel further includes:
 i. a Y-cut lithium niobate crystal to sense deflections of the detector wing, wherein the Y-cut lithium niobate crystal is positioned such that its Y-axis is perpendicular to the deflection of the detector wing; and 
 ii. a pair of electrodes fused to the Y-cut lithium niobate crystal by metal, wherein the electrodes extend though the housing. 
   
     
     
         13 . The vortex shedding flow meter of  claim 12 , wherein the shroud defines a hole into which the housing is seated, and at least one arcuate structure such that the housing may fit within. 
     
     
         14 . The vortex shedding flow meter of  claim 12 , wherein the housing includes an upwardly extending extension. 
     
     
         15 . The vortex shedding flow meter of  claim 14 , wherein the extension includes a cover piece that substantially surrounds the extension. 
     
     
         16 . The vortex shedding flow meter of  claim 12 , wherein the housing further includes a temperature sensor.