Device and method designed for ultrasonically inspecting cylinders for longitudinal and circumferential defects and to measure wall thickness

Abstract

Methods and apparatus for ultrasonically scanning cylinders are provided. The methods and apparatus employ as few as one ultrasonic sensor for full immersion scanning and defect detection. Self-centering fixturing spins the cylinder, reducing vibration, allowing for fast ultrasonic scans. To create the 45 degree angle beam shear waves for the circumferential scans, the ultrasonic sensor is offset from the centerline of the cylinder, creating the correct angle for excitation of the shear wave.

1 - 26 . Cancelled  
   
   
       27 . A method of testing for the presence of a container defect, comprising: 
 immersing a container in water;    spinning the container in the water;    moving an ultrasonic transmitting/receiving transducer into proximity with a first circumferential region of the container, which first circumferential region is located at a first angle relative to a central axis of the container;    moving the ultrasonic transmitting receiving transducer along the first circumferential region for a first length while transmitting a first set of ultrasonic pulses from the transmitting/receiving transducer into the container;    detecting a first set of signals resulting from the first set of ultrasonic pulses;    moving the ultrasonic transmitting/receiving transducer into proximity with a second circumferential region of the container;    moving the ultrasonic transmitting receiving transducer along a second length of the second circumferential region while transmitting a second set of ultrasonic pulses from the transmitting/receiving transducer into the container, which second circumferential region is at a second angle relative to the central axis of the container, wherein the first and second angles are different;    detecting a second set of signals resulting from the second set of ultrasonic pulses; and,    determining from the first and second detected sets of signals whether a defect is present.    
   
   
       28 . The method of  claim 27 , wherein the container is a cylinder.  
   
   
       29 . The method of  claim 27 , wherein container is rotated in an container defect detection apparatus, the apparatus comprising: 
 a fluid tank which holds the water;    a rotatable cup mounted within the fluid tank, which rotatable cup is configured to receive a first region of the container;    a rotatable cap configured to receive a second region of the container;    an engagement mechanism which moves the first or second rotatable mechanism towards or away from each other to engage the container; and,    a drive train coupled to the rotatable cup or the rotatable cap, which drive train turns the rotatable cup or rotatable cap;    wherein the container is rotated by engaging the rotatable cup and rotatable cap against the container by activating the engagement mechanism, and rotating the rotatable cup and rotatable cap with the drive train.    
   
   
       30 . The method of  claim 29 , further comprising transporting the container defect detection apparatus to a site proximal to the container prior to mounting the container in the container defect detection apparatus.  
   
   
       31 . The method of  claim 27 , wherein the transmitting/receiving transducer is moved into proximity with the first circumferential region of the container such that a 45 degree shear wave is propagated in a wall of the container.  
   
   
       32 . The method of  claim 27 , wherein the transmitting/receiving transducer is moved into proximity with the first circumferential region of the container above the central axis of the container such that a 45 degree shear wave is propagated in a wall of the container.  
   
   
       33 . The method of  claim 27 , wherein the transmitting/receiving transducer is moved into proximity with the first circumferential region of the container below the central axis of the container such that a 45 degree shear wave is propagated in a wall of the container.  
   
   
       34 . The method of  claim 27 , wherein the transmitting/receiving transducer is positioned proximal to the first or second circumferential regions of the container to provide a longitudinal scan of a wall of the container.  
   
   
       35 . The method of  claim 27 , wherein the transmitting/receiving transducer is positioned proximal to the first or second circumferential region of the container to provide a circumferential scan of a wall of the container.  
   
   
       36 . The method of  claim 27 , wherein the receiving/transmitting transducer is mounted on a search tube which is coupled to a rotatable search tube holder, wherein the rotatable search tube holder is coupled to an x-y-z translation mechanism which comprises an x-axis linear table, an x-axis motor which drives the search tube holder along the x-axis linear table, and x-axis encoder which tracks motion of the search tube holder along the x-axis linear table, a y-axis linear table, a y-axis motor which drives the search tube holder along the y-axis linear table, a y-axis encoder which tracks motion of the search tube holder along the y-axis linear table, a z-axis linear table, a z-axis motor which drives the search tube holder along the z-axis linear table, and a z-axis encoder which tracks motion of the search tube holder along the z-axis.  
   
   
       37 . The method of  claim 36 , wherein the receiving/transmitting transducer is positioned proximal to the first or second circumferential region by engaging one or more of: the x-axis motor, the y-axis motor, or the z-axis motor.  
   
   
       38 . The method of  claim 36 , wherein the receiving/transmitting transducer is moved along the first or second length of the first or second circumferential region by engaging one or more of: the x-axis motor, the y-axis motor, or the z-axis motor.  
   
   
       39 . The method of  claim 36 , wherein the receiving/transmitting transducer is moved with the x-y-z translation apparatus, which apparatus is controlled by a computer operably coupled to the x-axis encoder, the y-axis encoder, and the z-axis encoder.  
   
   
       40 . The method of  claim 27 , further comprising: 
 moving the ultrasonic transmitting/receiving transducer into proximity with a third circumferential region of the container;    moving the ultrasonic transmitting receiving transducer along the third circumferential region for a third length while transmitting a third set of ultrasonic pulses from the transmitting/receiving transducer into the container; and,    detecting the third set of signals resulting from the third set of ultrasonic pulses.    
   
   
       41 . The method of  claim 40 , further comprising: 
 moving the ultrasonic transmitting/receiving transducer into proximity with a fourth circumferential region of the container;    moving the ultrasonic transmitting receiving transducer along the fourth circumferential region for a fourth length while transmitting a fourth set of ultrasonic pulses from the transmitting/receiving transducer into the container; and, detecting the fourth set of signals resulting from the fourth set of ultrasonic pulses.    
   
   
       42 . The method of  claim 41 , wherein the first, second, third and fourth set of pulses provide for one or more of: a circumferential scan of a wall of the container, a thickness scan of a wall of the container, and a longitudinal scan of a wall of the container.  
   
   
       43 . The method of  claim 41 , further comprising: 
 moving the ultrasonic transmitting/receiving transducer into proximity with a fifth circumferential region of the container;    moving the ultrasonic transmitting receiving transducer along the fifth circumferential region for a fifth length while transmitting a fifth set of ultrasonic pulses from the transmitting/receiving transducer into the container; and,    detecting the fifth set of signals resulting from the fifth set of ultrasonic pulses.    
   
   
       44 . The method of  claim 41 , wherein the first, second, third, fourth and fifth set of pulses provide for one or more of: a circumferential scan of a wall of the container, a thickness scan of a wall of the container, and a longitudinal scan of a wall of the container.