Water & Wastewater Treatment

WATER MANAGEMENT AND DATA 20 Water & Wastewater Treatment March 2014 Micronics ULTRAFLO D5000 Non-Contacting Doppler Flow Meter Permanent Flow Meter for Accurate Measurement of Dirty or Aerated Liquids from Outside the Pipe. Ideal to measure full pipe flow of any liquid containing gas bubbles or solids > 100 microns and recommended for: Sewage, Treated Wastewater, Aerated Water, Sludge and Slurries, Viscous Liquids, Abrasives, Food Products, Pulp Stock, Acids and Caustics. Simple installation and calibration and No Contact = No pipe cutting, maintenance, sensor fouling, pipe obstruction, pressure drop or corrosion! n Displays, Datalogs, Transmits, Totalizes and Controls Flow in Closed Pipes n Ideal for Problem, Dirty or Contaminated Liquids n External Non-invasive Ultrasonic Sensor n No Contact, No Maintenance www.micronicsflowmeters.com or call +44 (0) 1628 810456 0811-Micronics Half Page UF D5000 Ad 87 x 270mm update v1.indd 1 19/08/2013 18:16 operate in extremely arduous conditions, usually on pipes which have several bends. It must also meet the criteria of minimum installation cost and low maintenance requirements to satisfy the key water companies' driver of reducing operational expenditure. Generating such essential data has been in train for several years now as the regulator has driven MCERTS requirements for flow to be measured at a treatment works. As a result, the easier applications have been delivered by all the water companies. However, as we enter AMP6 (2015-2020), the spotlight is on the more challenging applications, some of which will cost several thousands of pounds in infrastructure cost alone before a single measurement is taken. The search for innovative technology solutions to capture data at the lowest cost is now at the forefront of discussions between technology manufacturers and water companies. The aim is to ensure the measurement of the process variables, without incurring significant expenditure to ensure access. Data intelligence As the demand for information increases, part of any strategic data measurement discussion will be the basic interrogation of the current data collection and measurement status. For example, is it already being measured? However, the most important question to be asked concentrates on assessing the worth of the data being extracted. A good example of this would be temperature measurement. Existing instruments typically have an in-built temperature sensor and the measurement is available to capture via the chosen communication protocol, such as Profibus, Hart or Modbus, so the data exists at no extra cost. However, the requirement for the temperature data has to be thought through. Whilst the data is there, is anyone interrogating the reason given to collect data concerning the ambient temperature measurement of a transducer? Is it actually used? Temperature measurement could have a real part to play when it comes to remote assets such as a storm tank or any open tanks exposed to wind chill factor, and this is only one example. In-built temperature sensors, which exist on most instruments, could quickly and accurately provide temperature data across the treatment process and could provide an indication that there may be a freezing risk. For example, in pipes that flow intermittently (such as pumped flows on recirculation or polymer et cetera), if freezing goes undetected, a pump may not be able to perform because the pipe is frozen. This could cause expensive damage to pumps and the process. With uncertainty surrounding predictions for future harsh UK winters, accessing such operationally critical data intelligence may help safeguard water company infrastructure integrity. While the examples provided are compelling, the water industry itself needs to determine if the business requirements mean access to such extended data sources will make the sector more efficient, and help to give their customers a better service. nnn A version of this article first appeared online in WIPAC Monthly "The search for innovative technology solutions to capture data at the lowest cost is now at the forefront of discussions between technology manufacturers and water companies." POTABLE WATER TREATMENT & SUPPLY 21 March 2014 Water & Wastewater Treatment wwtonline.co.uk R outine checks of a raw water valve at a water treatment works (WTW ) in Wales revealed cavitation causing extensive and potentially fatal wear to a strategic flow control valve. Further investigations of the 'pin holes' by non- destructive testing of the valve at Dŵr Cymru Welsh Water's Pontsticill WTW near Merthyr Tydfil found that in less than five years, cavitation had put the valve in danger of imminent failure. Should the valve have failed completely, the works would have flooded and reinstatement would probably have taken several days, placing 70,000 customers at risk of losing supply. Although there was a replacement plug valve on hand, Dŵr Cymru Welsh Water (DCWW ) sought advice from valve specialist IVL Flow Control as to the suitability of this type of valve in this environment. On studying the available data, it was proved that the pressure differentials present could not be handled by this type of plug valve, and it would inevitably lead to a repeat of the cavitation problems and another potential loss-of-supply situation. IVL recommended a series 300, 600mm EOV control valve as an alternative, along with a technical assessment, which DCWW was happy to accept. Installation The difficult replacement was carried out overnight, and the removal of the existing valve and re-installation of the new valve was achieved within an eight-hour overnight shutdown period between 8pm and 4am, with IVL's engineers on hand to assist. Chris Holloway, production asset engineer at DCWW said, "We had noticed a problem with the old valve when we were carrying out regular checks of the raw water valve. There was water spraying out of very small holes in the valve body. "When it came to changing the valve - and the capital team told us they were going to change the type of valve - I was a bit concerned that that the operation of it would change and we would not be able to restart the works in the way we normally would. "On the night after the new valve was installed and everything was ready to go, we decided to try to bring on the works using the normal method, where we have to bring the flow on very quickly for the first 40ML/d, to make sure the DAFs [wastewater clarifiers] get a decent flow to start with. I was surprised that the flow came on so smoothly and did exactly what I was hoping it would do. All changes following this were much smoother than we were getting with the old valve." IVL says the new 600mm control valve at Pontsticill WTW is already showing that it is resistant to cavitation, performing within an accuracy of ±0.5% and controlling flows up from 'closed' to around 95Ml/d. The supplier says that in this application, the new control valve will have a lifetime of 20-30 years when serviced and maintained regularly. nnn Pin hole cavitation revealed the unsuitability of a valve installed at a treatment works in south Wales. IVL Flow control's director, Craig Stanners, explains how a replacement was selected Valve replacement averts flood risk Perspectives Client "The detailed planning, competent risk assessment and above all, leadership and teamwork to get the job done in such a short space of time overnight is highly commendable. The commitment, proactive approach and long-term solution for this essential work have been first class." Peter Perry, chief operating officer, DCWW Operator "Since the install of the new valve we have noticed that the changes to the flow required by network and the high-lift pumps, which can be as much as 20Ml/d at any one time, have been a lot smoother than before. The control of the chemicals, which are flow-paced from the front-end, has also improved enormously." Chris Holloway, production asset engineer, DCWW Supplier "Thankfully this type of work goes unnoticed by the general public, but when dealing with such large volumes of water from a health and safety and water quality point of view, the planning and effort that goes into ensuring a smooth transition has to be absolutely meticulous. This was a great example of teams working together to protect essential services and an excellent example of a positive intervention that will benefit both customers and the company." Craig Stanners, director, IVL Flow Control The new EOV control valve installed

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