Hired Videoscopes Reduce Cooling Tower Inspection Times
23 Apr 2007
Following a series of trials, ABB consultants have demonstrated that rented videoscopes from Ashtead Technology Rentals can save substantial amounts of money and time in the routine inspection of cooling towers.
According to Health Protection Agency figures, reported incidents of Legionnaires' Disease have more than doubled over the last 25 years in
Increased international travel may be a contributory factor, however wet cooling systems (cooling towers and evaporative condensers) have been the subject of increased attention and a number of initiatives are underway to improve the situation. Control of Legionellosis is currently a major topic for the HSE.
Poor compliance with the requirements of the COSHH regulations and the HSE Approved Code of Practice (L8: ‘Legionnaires' disease: The control of legionella bacteria in water systems’) have, in conjunction with poor cooling tower control, been found to give rise to the potential conditions in which the growth of Legionella bacteria can occur.
However, since 1997, there has been a programme of action to improve levels of compliance and the inspections of installations, in conjunction with high levels of enforcement, have become important features of the programme.
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, a company that specialises in high-tech instruments for hire.
ABB offers a range of services providing cooling system optimisation under the umbrella of its Engineering Services Division. Water Technologist Melvin Hall says “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.”
Ashtead’s Andy Cleaver says “The iPLEX range of endoscopes are extremely flexible inspection tools, finding application in a wide variety of applications. We have many customers, in almost every industry, that need to undertake visual inspections in areas that are difficult to access and the facility to rent an iPLEX provides them with the latest technology that would otherwise be expensive to purchase.”
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.”
In summary, following work at a number of sites, ABB has demonstrated that hired videoscopes can reduce inspection times, and thereby minimise shut-down times from as much as 2 days down to as little as one hour.
For further information, contact:
1.
Ashtead Technology Rentals
Campus Five, Letchworth Business Park
Letchworth, HertfordshireSG6 2JF
Tel. 0845 270 2707
Email james.carlyle@ashtead-technology.com
www.ashtead-technology.com
2. Melvin Hall
mel.hall@gb.abb.com
Tel. 01925 741279
