Single-body dual-chip orthogonal sensing transit-time flow device using a parabolic relecting surface

Abstract

An ultrasonic sensor, including methods of using and installing same, the sensor having a pair of ultrasound transducers adapted to be inserted in, and being able to perform at, a single site of introduction into a duct. The ultrasonic sensor measures a forward ultrasonic path transit time and a second reverse ultrasonic path transit time of ultrasound signals propagating in a fluid, the arrangement being such that a comparison of the signal associated with ultrasound travel in one direction with the signal associated with ultrasound travel in the opposite direction enables the flow rate of the fluid in the duct to be determined. The ultrasonic sensor may utilize a curved reflecting surface on the duct and a reflective surface of an ultrasonic sensor end cap to provide forward and reverse ultrasonic W-shaped paths.

1 . A method of installing an ultrasonic sensor into an existing duct assembly, comprising: 
 removing an existing fluid sensor from an existing duct assembly;    mounting a retrofit assembly, including a boot structure with a mounting flange, to the duct assembly, the duct assembly including a duct for providing a flow path for a fluid;    machining a curved reflecting surface;    removing contamination from the boot structure; and    installing an ultrasonic sensor.    
   
   
       2 . The method of  claim 1 , further including collecting the contamination in the boot structure during the machining step.  
   
   
       3 . The method of  claim 1 , wherein the reflecting surface is machined into an interior surface of the duct.  
   
   
       4 . The method of  claim 1 , wherein the reflecting surface is machined so as to have a parabolic or spherical configuration.  
   
   
       5 . The method of  claim 1 , wherein the ultrasonic sensor includes a first transducer to transmit a signal, a second transducer to receive the signal, and an end cap, said end cap enclosing and isolating said first and second transducers from said fluid and having a reflective surface in contact with the fluid.  
   
   
       6 . The method of  claim 5 , wherein the first and second transducers are oriented at an angle with respect to an axis orthogonal to a central axis of the duct.  
   
   
       7 . The method of  claim 5 , wherein the reflecting surface is machined into a wall of the duct located opposite said reflective surface.  
   
   
       8 . The method of  claim 7 , wherein the ultrasonic sensor is installed such that the signal transmitted by the first transducer approximately traverses a W-shaped path that extends from the first transducer to the curved reflecting surface, then to the reflective surface, then to the curved reflecting surface, and finally to the second transducer.  
   
   
       9 . The method of  claim 1 , wherein, in the last step, the ultrasonic sensor is installed so as to be flush with the interior wall of the duct.  
   
   
       10 . The method of  claim 1 , wherein said contamination is removed using a vacuum source.  
   
   
       11 . A method of retrofitting an existing duct assembly with an ultrasonic sensor, the method comprising: 
 removing an existing fluid sensor from an existing duct assembly so as to expose an existing hole pattern in the duct assembly, said duct assembly including a duct for providing a flow path for a fluid;    mounting a retrofit assembly, including machining equipment and a boot structure, to the duct assembly;    inserting the machining equipment through the hole pattern to machine a curved reflecting surface in the duct while containing metal shards in the boot structure;    withdrawing the machining equipment through the hole pattern;    removing contamination from the boot structure; and    installing an ultrasonic sensor in place of the removed fluid sensor.    
   
   
       12 . The method of  claim 11 , wherein the reflecting surface is machined into an interior surface of the duct.  
   
   
       13 . The method of  claim 11 , wherein the ultrasonic sensor is a flow sensor and includes a first transducer to transmit a signal, a second transducer to receive the signal, and an end cap, said end cap enclosing and isolating said first and second transducers from said fluid and having a reflective surface in contact with the fluid.  
   
   
       14 . The method of  claim 13 , wherein the reflecting surface is machined into a wall of the duct located opposite said reflective surface.  
   
   
       15 . The method of  claim 14 , wherein the ultrasonic sensor is installed such that the signal transmitted by the first transducer approximately traverses a W-shaped path that extends from the first transducer to the curved reflecting surface, then to the reflective surface, then to the curved reflecting surface, and finally to the second transducer.  
   
   
       16 . The method of  claim 13 , wherein the first and second transducers are oriented at an angle with respect to an axis orthogonal to a central axis of the duct.  
   
   
       17 . The method of  claim 11 , wherein the reflecting surface is machined so as to have a parabolic or spherical configuration.  
   
   
       18 . The method of  claim 11 , wherein, in the last step, the ultrasonic sensor is installed so as to be flush with the interior wall of the duct.  
   
   
       19 . The method of  claim 11 , wherein said contamination comprises the metal shards and is removed using a vacuum source.