Skip to main content
padlock icon - secure page this page is secure

An automated ultrasonic inspection method for thickness checking of dryer cylinders for paper making machines

Buy Article:

$22.00 + tax (Refund Policy)

Paper machine dryer cylinders are steam heated cast iron cylinders typically 7.2 m long by 1.5 m diameter with a wall thickness of between 25 and 35 mm. In-service inspection requirements specify that dryer non-destructive testing is performed to the standard document TIS-0402-16: ‘Guidelines for the Inspection and Non Destructive Examination of Paper Machine Dryers’. This Standard requires periodic thickness surveys to be conducted to assure that the shell thickness is consistent with the maximum allowable working pressure.

Ultrasonic thickness readings can determine the worn or thin spots that threaten the integrity of the dryer, but problem exists in using conventional pulse echo techniques. Accurate ultrasonic thickness measurement depends on consistency in the material properties between the calibration test-piece and the work-piece. On any given dryer cylinder the material properties of the cast iron and therefore the velocity of sound varies over the length and around the circumference. Therefore, reliable and accurate thickness measurements cannot be made from a single point calibration and it is physically impossible to obtain multi-calibration points on a dryer cylinder using a conventional pulse echo technique.

This paper describes the development and application of a self-calibrating ultrasonic imaging system using aspects of the time-of-flight diffraction (TOFD)method to provide a cross section image and accurate point readings along the whole length of a dryer cylinder. This enables accurate, rapid monitoring of the vessel thickness and a reliable on-going hard-copy record of the test.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
No Metrics

Document Type: Research Article

Affiliations: Genesis Power Ltd at Huntly Power Station in New Zealand

Publication date: September 1, 2003

More about this publication?
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more