Coal Silo Inspection: How Zenith Increases Speed, Reduces Risk, & Saves Costs While Gathering Enhanced Data

The inspection of hard-to-reach, vertical assets have long been a challenge to inspect. Traditional management often includes the erection of scaffolding and/or rope access into confined spaces by human inspectors to adequately visualise and gain data.

Coal silos are one such example. The Omaha Public Power District in Nebraska, USA, was keen to find an alternative to such methods and approached Interactive Aerial to create a solution. The challenges involved in this scenario were as follows:

• These coal silos were prone to corrosion degradation, thanks to the configuration of carbon steel with stainless steel liners.
• The geometry of the assets – suspended cones – was particularly difficult to inspect.

The vital importance of regular inspection with high-quality data gathering can’t be over-emphasised. The infrastructure of the entire plant is dependent on the integrity of these coal silos, and preventative inspection and maintenance are crucial.

This particular scenario was achieved using an innovative system called Zenith.

Zenith: A 21st Century Solution

Zenith is a 4K vertical inspection tool that’s been designed specifically to carry out NDT in hard-to-reach space. Not only does it remove the need for expensive shutdowns and human entry to assets, such as coal silos, but it has an impressive 500+ foot reach and 360-degree viewing.

Zenith is placed at the top of an asset and, thanks to a unique design, can even overcome challenges where entry to the vertical asset is offset from the launch point. This particular inspection did not need this, plus there were no internal barriers to navigate. However, the silos did present an additional challenge: they were wide and the stainless steel liner was very reflective. 

The service team was able to use the many customisable elements of Zenith to overcome all of the inspection issues, as follows:

• Zenith hangs from a cable and is free spinning: The camera is stabilised and can capture both 4k video and 18MP images with a 30x optical zoom
• Overcome the lighting issue: Zenith is custom-fitted with a 10,000 lumen LED. However, the width and reflection meant that this wasn’t quite enough to gain the visual acuity necessary for the images of the welds. An add-on lighting payload was suspended beneath Zenith to overcome this, meaning the visuals were carried out exactly as per customer requirements. This attachment capability is also ideal for other payloads, such as thermal and radiation sensors, etc.
• Zenith is remotely controlled: After the equipment has been set up, the inspection is remotely carried out away from the asset. It’s also designed for easy operation, with no prior training or certifications needed.
• Inspection time is dramatically reduced: Including set up and tear down, the inspection time of each silo was only 25 minutes.

Thanks to the use of Zenith to carry out the inspection, the team carried out the task in a single business day. This was half the time that had been set aside for the inspection and far less than would have been required for a more traditional approach.

The advantages of such innovative solutions are multiple:

• Faster, more cost-effective inspections
• Reduced risk, thanks to removing the need for human entry
• Highly accurate data capture
• Reduced costs – lower insurance, less asset downtime

Very importantly, easing the historically expensive and risky inspection process allows companies to embrace a far more proactive maintenance programme. Easily carried out preventative inspection brings many advantages:

• Reducing the risk of unexpected breakdown, maintenance and downtime
• Increased compliance with regulations
• Lowered insurance costs
• Customer and employee confidence
• Reduced maintenance costs

In short, the use of remote inspection tools, such as Zenith, is the future of asset inspection. Decades of research and design are culminating in real-world solutions that forward-thinking industry players are taking full advantage of. However, one sticking point is the ‘it’s always been done that way’ mentality, with many being hesitant to utilise such radical approaches.

But as the technology becomes more commonplace and affordable, it’s predicted that outdated inspection processes that involve lengthy shutdowns and human risk will become less and less tempting. In fact, companies that fail to look to such methods will soon be at a distinct disadvantage as their competitors realise the benefits.

Zenith is just one example of the future of NDT. Other robotic benefits, both semi-autonomous and autonomous, are set to revolutionise how these are carried out. Such technology is no longer futuristic – because that future is today – and it’s something we should all be looking to use.