FEATURE PUMPS, VALVES & ACTUATORS A SMARTER SOLUTION TO SLUDGE HANDLING
A successful trial of SEEPEX’s Smart Air Injection (SAI) technology has resulted in the installation of several units at Thames Water’s Riverside project
P
rogressive cavity pump specialist SEEPEX has developed a new system
to improve dewatered sludge handling, enabling long distance transfer with reduced operational costs by using a combination of PC pump technology and dense-phase conveying. The SAI (Smart Air Injection) technology has already been trialled by Thames Water at its Reading Sewage Treatment Works (STW) and is now being installed as part of the new Thames Water Riverside project to provide an energy-efficient alternative to conventional sludge handling systems. SEEPEX and Thames Water have worked
together for many years. As the UK’s largest water and sewage treatment company, Thames Water provides wastewater services to 15 million customers and is committed to reducing its energy consumption. Its interest in SAI was linked to a new project at Riverside STW to handle dewatered sludge. Following a visit by Thames Water
representatives to observe SAI in action in Sweden, the company decided to measure the potential energy savings it could make by installing a trial SAI system at its Reading STW. This trial set out to not only prove the technology, but to quantify the additional energy savings that could be delivered by pumping the dewatered biosolids from the centrifuge discharge to the storage silo. A SAI trial unit, including full controls and monitoring, was installed on the existing SEEPEX multistage PC pumps and the results were recorded. During the trial, energy use and
discharge pressure measurements were taken. Using these figures, together with the volume and height of the discharge pipework, SEEPEX engineers could then calculate the optimum amount of air required. The trial concluded the energy saving with SAI compared to a multistage PC pump without air injection was 15%. Compared to the original piston pumps used at the site, the energy saving was an astonishing 61%. However, there were even greater
savings to be made by switching to a single stage SAI pump fitted with SEEPEX’s Smart Conveying Technology (SCT), instead of the multistage pumps currently in use. Air usage data from a working SAI installation using SCT pumps in Belgium, enabled SEEPEX to produce an estimate for Thames Water, based on the trial results from Reading. It concluded that, if SCT single stage pumps were used in place
12 APRIL 2019 | PROCESS & CONTROL
of multistage pumps, the energy saving at Reading STW would be approximately 40%. When compared to the original piston pumps, an SAI system with SCT pumps would reduce energy consumption on this application by approximately 75%. As a result, Thames Water has procured
several of SEEPEX’s SAI units for its Riverside project. “We were faced with a particularly tough challenge at Riverside,” explained Paul Fountain, senior consultant
– Biosolids, for Thames Water. “Replacing a problematic conveyor system with proven PC pumps was the preferred solution, but due to very tight space constraints, low access walkways and a labyrinth of pipework to work around, the traditional multi-stage pump was not going to be possible.” “Working with SEEPEX, we decided to
purchase several single stage Smart Conveying Technology PC pumps, coupled with SEEPEX Smart Air Injection innovation,” continued Fountain. “This allowed us to significantly reduce the pump length and installed motor powers, and has the added benefit of ease of maintenance.” Smart Air Injection technology works in
Reading STW had previously used piston pumps, but as a result of process limitations and high operating costs, Thames Water switched to SEEPEX’s multistage PC pumps in 2014. This solution halved Thames Water’s energy use, as well as reducing transport and maintenance costs. Four years on, it was time to see if SAI could improve things further (top)
SEEPEX’s smart air injection technology is an energy-efficient alternative to
conventional sludge handling systems (above)
the following way. A solid ‘plug’ of dewatered sludge is formed by an open hopper pump, which is then split into smaller plugs and transported onwards using compressed air in the discharge pipework. Air injection is tailored to each application on-site, using algorithms to ensure that the discharge pressure remains below 4 bar. The sludge plug is lubricated with boundary layer liquid, which reduces friction losses in the pipework and improves the energy efficiency of the system. Adjusting system parameters such as plug length, boundary layer liquid and air volumes on-site makes it possible to set application-specific, energy efficient, operating parameters. In addition, SAI is an automated system,
with connected services to allow for real- time pump monitoring. Smart control is integrated into existing automation and control systems via conventional interfaces, enabling remote monitoring of pump and system performance. This optimises process conditions, saves energy and increases pump service life. All functional components, sensors and actuators are part of the scope of supply, and are integrated into the SAI control software, configured to each application. Already in operation at a number of sites
The SAI technology is being installed at Thames Water’s Riverside STW to handle dewatered sludge
throughout Europe, SAI is now set to improve sludge handling at the Riverside project, and beyond. At a recent seminar held at Thames Water’s Reading site, delegates from UK Water plc enjoyed a demonstration of the technology in real time and were able to identify areas of their processes that could benefit from SAI. Potential improvements that were highlighted included: increasing the dry solid content (ds%) of sludge, where plant layout and high discharge pressure has limited it to date; removing problematic conveyors; and replacing legacy pumps with more energy efficient SCT models.
SEEPEX
www.seepex.com
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
