Cooling tower inspections include a physical examination of the cooling pack to check for scale, slime, algae and physical obstructions, any of which could harbour Legionella bacteria as well as hamper the performance of the cooling system.
In the past, it has been common practice to remove the cooling pack for the purposes of the inspection and cleaning (regardless of whether the tower needed to be cleaned or not). However, depending on the size of the unit, this can take anything from a few hours to two days to complete. During this time the cooling system would be shut down resulting, in many applications, in the closure of the entire facility. However, engineers at ABB have recently demonstrated that effective inspections can take place without having to remove the cooling pack. This has been achieved with the use of hired high-resolution videoscopes from Ashtead Technology Rentals.
ABB offers a range of services providing cooling system optimisation under the umbrella of its Engineering Services Division. Water Technologist Melvin Hall comments: "Cooling tower inspections have always formed a critical component of ABB's 'Total Cooling System Management", however, removal of the cooling pack has imposed substantial penalties and risk (working at height, in confined spaces) for our customers so we have been looking for alternative effective inspection methods that would not result in lengthy shut downs. Our work has indicated that the iPLEX videoscope is ideal for such work because it enables us to inspect the internal components of the tower from top to bottom using a small access point. The probe can extend up to almost 10 meters providing clear, 3-dimensional video images that can be stored or transferred to a PC.
“It is possible to rent the videoscopes from Ashtead, thereby avoiding the large capital cost of purchase. The instruments are delivered precisely when they are needed and in excellent condition. They are also very easy to use, but Ashtead offer technical support both on-site and by telephone so customers are able to start recording images almost immediately.”
One of the key features of the iPLEX range is the quality of images that are generated. Images with a limited dynamic range tend to lose detail in the brightest and darkest areas. However, the iPLEX instruments have virtually eliminated such whiteout and blackout through a newly developed, proprietary image-processing algorithm that greatly expands the dynamic range. The resulting rich gradations naturally represent the inspection area as seen by the naked eye, allowing much more accurate inspection. Consequently, Melvin Hall says he is “confident that, in most cases, deployment of the iPLEX endoscopes from Ashtead can negate the requirement to dismantle cooling packs for the purposes of inspection.”
For further information please visit: www.ashtead-technology.com