Triple edge challenges

Companies are constantly striving to increase their ROI and Buckingham-based TTL, in response to requests from its gas turbine customers, recently revisited an application that was first looked at around 10 years ago, but deemed untenable at the time.

The so-called ‘Triple-Edge Repair' – the bringing together of aerofoil tip, leading edge and trailing edge repairs into one combined operation is a challenging operation and not for the faint hearted! Difficulties in achieving accurate and consistent results have been more to do with mechanical, rather than software limitations. The need to leave all three edges exposed for probing and machining has, in the past, compromised the mechanical rigidity of the process and as a result, the process has for the most part been split down into two or more separate operations.

TTL has recently resurrected the Triple-Edge repair on HP compressor blades and has already completed machining trials – with encouraging results, the company claims.

The solution makes use of a new machine mounted laser digitising system which is said to significantly decrease the time taken to measure blades and provide other advantages. The ability to measure right up to the weld/parent material interface contributes significantly to achieving good blend quality and with a new approach to fixturing and machining, the way is being paved for a cost-effective solution.

“Although this work is still in development, when completed it will provide lower capital and operational costs, fewer machine visits by the operator and a greater return on investment,” reported TTL's managing director Paul Walton.

TTL
www.ttl-solutions.com