WET News

DECEMBER 2016 WET NEWS 17 Drain Brain What is the greatest cover depth over a pipe or most effi cient bedding design for an installation? How do I air test a pipeline? And what's the optimal size of manhole for a given size of pipe? The CPSA Guide has the answers to all these questions and more. Updated for the latest industry specifi cations, it's an invaluable resource for anyone looking to design and build effi cient drainage and SuDS systems. And it's absolutely free. Download your copy today at www.concretepipes.co.uk/technical-guide What is the greatest cover depth over a pipe or most effi cient bedding design for an installation? How THE CONCEPT • Truck-loading silos using sliding-frame technology and screw conveyors enable greater volumes to be handled in a shorter space of time • A sliding frame mechanism can undercut the full section of the silo's contents to prime a screw trough • Truck-loading silos can ensure greater security from foreign object debris contamination NEED TO KNOW 1 Unnecessary demurrage and reception blockage costs are minimised 2 Some storage silos may be cheaper, but may be of an inferior design and quality which can result in problems with bridging and discharging 3 A constant, precisely metered volumetric flow of friable sludge is critical to AD and thermal hydrolysis systems THE VERDICT "Industry sources suggest that the cost saving of transporting sludge stock to hubs is largely determined by distance and load volumes from its satellite sites. Typically, the saving is around £10,000 to £17,000 per month for a 100m 3 truck loading silo compared with an existing 2-3 RO-RO container system. For a 240m 3 truck loading silo the saving could be in the region of £27,000 per month" Mark Neal, Saxlund International Charity partner SUppOrteD By SUppOrteD By WATER NORTHERN IRELAND CONFERENCE 23 FEBRUARY 2017 | BELFAST book now events.wwtonline.co.uk/ni InvestIng In HealtH, tHe economy & tHe envIronment This is the only event that brings all the major stakeholders together to address the economic, environmental and customer service challenges facing the Northern Ireland water sector. chris Hazzard mla Minister for infrastructure sara venning Chief executive officer Northern Ireland Water brian mcHugh Finance & network assets director Utility Regulator catriona Davis Chief inspector of drinking water Drinking Water Inspectorate David Porter Chief executive DfI Rivers Agency gerry millar Director of property and projects Belfast City Council bill gowdy Director of engineering and procurement Northern Ireland Water eXpert SpeaKerS inCLUDe: ● Gain insight into the Department for Infrastructure's investment priorities ● Explore Northern Ireland Water's ambitious plans for PC15 and beyond ● Tailor your experience through dedicated streams on Drinking Water Quality, Environmental Protection and Wastewater Management transport and store, it also helps to make it more friable, stable, and safer to manage, while minimising odour. For those operators already using pumped cake, the move to chain or screw handling and storage benefits the cake composition, making it more AD-efficient and easier to spread by farmers. Friable sludge, free from foreign objects, handled without excessive force and with an accurate DS%, is what AD operators require for optimum performance. A constant, precisely metered volumetric flow of friable sludge is critical to anaerobic digestion and thermal hydrolysis systems and requires properly engineered solutions that take account of the materials' non- free flowing properties to avoid the risk of blockages. A measured flow ensures a homogenous discharge to the next process. The thermal hydrolysis process involves heating sludge to destroy any pathogens and degrading cell structures to create better flowing, good quality sludge making it easier for bacteria to digest and to produce methane. Selecting the right technical, environmental and economic solution, not only for water companies' current requirements but also for their The silos offer a quick turnaround, and also help to reduce odour anticipated future needs, makes sound sense. Extensive experience and a full understanding of the processes and risks are essential. It is also important for an industry partner to provide a complete, end-to-end quality solution for sludge storage and handling which includes design and construction, commissioning and maintenance. Technological innovations such as these in use by Southern Water and Anglian Water are completely changing the way the wastewater industry deals with converting sewage sludge to energy. In order to maintain economy of scale, efficiencies in advanced anaerobic digestion (AAD) at each hub, indigenous waste needs to be topped up, which means transferring sludge from satellite sites to central hubs. Robust bulk material handling solutions and advanced digestion systems are now commonplace in reducing fuel costs and carbon emissions whilst improving the efficient processing of wastewater and sewage sludge. Mark Neal is water specialist at Saxlund International.

• Cover