(20 min.) Case Study: Innovative approach in solving a high vibration issue on a Cooling Tower Machine Train

Muhammad Zeeshan Iqbal, Reliability & Performance Engineer, Territory Generation (Int.)

Description

Cooling Towers are an important piece of equipment on a power station. High vibrations can damage or at least prevent it to be used which can decrease overall plant performance. Our innovative approach will highlight the effectiveness of condition monitoring of cooling towers at a power station in Australia

Vibration Analysis involves the use, knowledge and experience gained from multiple years in an industrial environment. The basic equipment used can be an overall vibration meter which can display vibration amplitudes in a single direction. Although basic vibro-meters can show the levels but it will not identify the cause the source of troublesome vibration. Hence, we use spectrum analyzers or (vibration analyzers). These generate key plots such as spectrums, waveforms, orbits, etc. A vibration analyst can identify whether a machine has an imbalance, misalignment, resonance, etc. Channel Island Power Station has 04 sets of cooling towers. One of those cell units had high vibration problems for over a year. Vibration analysis was performed on this unit which revealed a possible misalignment problem. During routine vibration data collection, it was seen through the naked eye that the cooling tower drive shaft was wobbling. A slo-mo video was made with an iphone, which was instrumental in pinpointing the problem. The drive shaft was taken out and a run out check was performed. The shaft was out of center as predicted and could not be balanced on a balancing machine as the seam on the shaft would skip in the balancer. A new shaft from stock was installed and vibration amplitudes drastically reduced and were in acceptable region. <span style=”font-family:calibri,sans-serif; font-size:11pt”>Plant maintenance personnel were always in argument with the condition monitoring team’s assessment of the situation but eventually agreed after watching a video of the shaft wobble. Motion amplification is now being used in industrial environment to slow down the vibrating motion of machines and structures. This is a great aid in diagnostics of machine problem.

Bio

A graduate mechanical engineer with over 13 years of continuous experience in condition monitoring, machinery diagnostics, reliability engineering, power stations and asset management. Currently working for Territory Generation but have worked for GE Oil & Gas, Engie (formerly GDF Suez), ESB International and Western International. Hands on experience in vibration analysis, infrared thermography, oil analysis, ultrasonic analysis, partial discharge testing, boroscopic inspections, etc.