A MAINTENANCE MATTER
23 September 2011
With the Water Framework Directive (WFD) and the AMP (Asset Management Plan) 5 spending round now firmly on the agenda, there is increasing pressure on wastewater treatment works to improve efficiency and implement life cycle costing strategies. Simon Lambert, Sales and Marketing Director at Mono, explains how progressing cavity (PC) pump technology is evolving to help facilities meet the demands of modern wastewater treatment.
Due to be fully implemented by 2015, the objective of the European WFD is to integrate every aspect of the control of water quantity and quality in the water cycle across Europe, so that all parties work to one timetable and objective.
A central concern of the WFD is how water used for domestic, commercial and industrial purposes is treated and returned to the water courses. Not surprisingly, upgrading the effectiveness of treatment processes has been a priority in the current five year spending round.
The AMP 5 spending round is continuing this progress by focussing on improving the lifetime cost-effectiveness of the treatment processes. As such, treatment works will be encouraged to focus on lifetime costs and their improvement through better specification and assessment of equipment.
Trends in Treatment
As well as impending frameworks and directives, there are other factors that are impacting on treatment plants. For example, many treatment works are now centralising certain duties to improve efficiency and help deliver cost savings, so it is therefore essential that all equipment, and pumps in particular, can handle the larger capacities processed at main sites.
There is additional pressure placed on pumps due to the increase of non disposable waste entering the drains that needs to be processed. Items such as facial wipes, cleaning cloths and ‘disposable’ toilet brushes are being flushed into the sewers instead of being thrown in the bin.
For water and wastewater treatment works this can cause serious ragging issues at pump station collection. These inclusions are particularly damaging to centrifugal pumps, as the propeller vanes and shaft can be totally entangled.
Widely known for their ability to easily and efficiently transfer a number of difficult media, the performance of progressing cavity (PC) pumps can have a considerable bearing on how energy and cost efficient a treatment works is, as well as its quality of discharge.
However, even with the use of screens and grinders, PC pumps can still suffer from ragging and maintenance issues. Coupled with these new problems facing the industry, such as diminishing in-house expertise and unsuitable items finding their way into the sewers, difficult processes are becoming even more of a challenge.
As such, leading pump manufactures have developed new pump technology. This has been specifically designed to provide a quick and easy way to disassemble, de-rag and maintain a PC pump in-situ, eliminating the costly maintenance and down time that servicing can often cause.
On average, this new type of maintain in place (MIP) PC pump technology can reduce the maintenance time needed to replace a rotor, stator, coupling rod and joint by up to 95%. The average time to completely strip down and replace the drive train elements is usually one full day on typical sludge pumps; with this new MIP pump it takes just 30 minutes.
The chamber of this new MIP pump has a two piece design, which can be dismantled and assembled in place without requiring years of expertise. It can be opened up and rebuilt with a spanner and an Allen key in a fraction of the time previously required.
A Growing Family
Keen to maximise the potential of this revolutionary technology, leading manufacturers have since developed further MIP solutions, all designed to help make maintenance easy for customers.
Providing engineers with the option to install a complete MIP package, leading manufactures have also developed a new range of grinders which can significantly reduce the costly downtime that inspection and maintenance of this technology can often cause.
The new MIP grinder technology is specifically designed to meet on-site tanker discharge and sludge/fat processing by protecting downstream equipment from blockages. It also allows quick and easy inspection and maintenance, without the need to disconnect any pipework.
While existing grinder technology requires that the removal of cutting elements from a typical grinder or macerator is taken off site, often taking up to two days to complete, the cutter stack of this new technology can be inspected and replaced within two and a half hours.
Installation is simple, with in-line flanges or the option of tanker coupling connections. Quick release inspection covers allow in-situ replacement of the cutters and these can be specified to 8.0mm, 5.5mm and 3.0mm thickness to match the optimum particle size for specific process requirements.
Looking to the Future
The next generation of PC pump and grinder technology have been designed to ensure treatment works can continually improve their processes and cope with the increasing demands of our growing population.
As such, these solutions can play a key role in sewage treatment works by considerably improving maintenance downtime and whole life costs. Perhaps more importantly, they also enable them to meet the requirements of the AMP 5 spending round and the WFD, helping them to safeguard funding moving forward.
For further information, please visit: www.mono-pumps.com