PC-SEP22-PG32.1_Layout 1 12/09/2022 09:57 Page 32


WATER & WASTE TREATMENT


A FRESH APPROACH TO FLOW METERING


FLEXIM outlines the benefits of non- invasive flow measurement in two different water applications


N


on-invasive flow measurement is highly sensitive to low flow velocities and can be used flexibly, which is why


clamp-on ultrasonic flowmeters are proving invaluable for the accurate measurement of wastewater. They are suitable for this application, or any dirty liquid that’s sonically conductive or water based. Clamped to the outside of the pipe, they use ultrasound to reliably measure flow, even with high solids content. Transducers are robustly clamped on the pipe and sound bounces back and forth, with the difference being proportionate to the velocity. FLEXIM was called in to assist with delivering


a fresh approach to flow measurement at a German pond treatment plant. With plans to modernise and convert it into a compact plant, the engineers were looking for an alternative to their current measuring method used to assess the cleaning performance. In order for the plant to go ahead with its expansion plans, the present actual output must first be determined and dry weather inflow rate must be measured in order to estimate future capacity needs, and to determine the cleaning performance. The normal way to carry out this


measuring task is to direct the water flow that needs to be recorded through a pipe, and to ensure that it’s always full, it needs to be designed as a culvert. A collection container was constructed with an attached pipe with a 90° upwards bend, so that the pipe is always permanently filled. The engineers were using a magnetic-


inductive flowmeter installed on the DN200 line, but this was only proving to be up to the


T


measuring task to a certain extent. Due to the low inflow and the resulting low flow velocities, the amount of wastewater discharged would often remain unrecorded. FLEXIM replaced this with a flowmeter with a lower flow response threshold. A key advantage of clamp-


on ultrasonic measurement is that the technology can be used to set up flow measuring points without having to open the respective pipeline. And because the acoustic method works practically without inertia, even the smallest currents are accurately recorded. Ultrasonic flowmeters are not only used for


balancing, but also for leak detection by monitoring low flow rates at night. Following the switch to ultrasonic


technology, the bespoke culvert measurement point now reliably records the amount of wastewater fed into the sewage treatment plant. And once the sewage treatment plant has been modified as planned, it will be a simple task to uninstall the clamp-on flow meter and reuse it at a new measuring point, making non-invasive ultrasonic measurement technology truly versatile, and the solution of choice for many years to come. In another application at river water


pumping stations, the goal was to help conserve and improve precious groundwater using reliable and accurate non-intrusive flow measurement. Because non-invasive clamp-on ultrasonic


MUNCHER INCREASES GAS YIELD BY EIGHT PER CENT


he installation of a Fluid Motion Solutions’ (part of NOV Inc) Mono Muncher at a biogas plant in Spain has helped increase gas yields by eight per cent.


Designed for the homogenization of sludge in digestion,


feeding and recirculation, the inline Mono Muncher’s tearing, shearing and crushing action has removed a bottleneck in the system that was causing blockages, downtime and extra maintenance. Supplied with a custom-designed control system, the /hour flowrate shredder has a proven track record of


180m3


protecting pumps from blocking by fine-grinding AD feedstocks such as municipal sludge and food waste. In the event of an object initially being too strong, the Mono Muncher’s overload protection technology reverses the cutters (to clear the cutter stack), with any solids falling into the trash trap. Fluid Motion Solutions


nov.com/industrial 3 SEPTEMBER 2022 | PROCESS & CONTROL 2


Ultrasonic flowmeters offer reliable


measurement of wastewater in a sewage


treatment plant


flowmeters are fixed to the outside of the pipe, the volume flow can be measured without process disruption. Sound waves calculate the transit time of a liquid, enabling even the smallest changes in upstream or downstream flow to be accurately monitored, which is key to effective consumption and leakage monitoring. Working with an Australian river water


pumping station that supplies irrigation water to farmers, FLEXIM assisted with flow measurement on large water mains. The underground water supply is valuable to the area, so the maintenance and management of this precious resource is vital. In order to reduce the overall consumption


at the pumping station, an upgrade project was implemented, which involved installation of the pumps with variable speed drives and clamp-on flowmeters on the rising mains. The operators were looking to retrofit old pipes with reliable and accurate measuring instrumentation, so FLEXIM worked to determine the best possible solution. Following a successful demonstration of the


ultrasonic technology, clamp-on flowmeters were installed at several of the Water Authority’s pumping stations. One particular old concrete pipeline had been relined with a 1,200mm HDPE pipeline during a prior upgrade project, and the grout between the liner and the concrete was unsuitable for ultrasonic measurement. The solution was to cut away a section of the concrete pipe and create a pit that would expose a portion of HDPE. This allowed the transducers to be installed straight onto the HDPE to guarantee the best possible signal. Twelve months after installation, a routine


inspection discovered that flooding had caused the pit to fill with silt. There had been no loss of signal whatsoever during this time, and all that was needed was a vacuum truck to suck up the silt and a simple hose down of the transducers.


FLEXIM www.flexim.co.uk


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70