FLUID HANDLING MODERNISATION PROJECT
SEEPEX
SEEPEX SAI Technology enables Veolia ’ s sludge cake handling system upgrade at Osberstown STF
The modernisation project for Osberstown STF managed by Veolia involved the upgrade from a very energy intensive thermal drying plant to advanced anaerobic digestion using their Exelys™ thermal hydrolysis process . The scope of supply also included a new dewatering plant with three belt presses and three sludge cake pumps to transfer the dewatered sludge into the THP feed silos .
COMPACT , ENERGY-EFFICIENT AND FLEXIBLE SYSTEM FOR COMPLEX PROCESS
The upgrade project presented an immediate challenge : how to fit the new THP and dewatering plant into the restricted space of the existing building . The compact design of Veolia ’ s Exelys™ process significantly reduced the installation space required for the THP .
However , due to the space restraints , using a conventional multi-stage pumping system required to transfer 18-27 % DS sludge cake through a total of 50m including vertical pipework with long-radius 90 ° bends would not be possible .
The dewatered sludge handling system needed to have the operational flexibility to accommodate a fully automated 24 / 7 operation with one , two or all three presses in operation at the same time , discharging into either of the two existing sludge cake silos through common discharge pipework .
LOW ENERGY AND LOW DISCHARGE PRESSURE SOLUTION FOR SLUDGE CAKE TRANSFER
Having worked together on many projects over the years , Veolia engaged with
SEEPEX to explore how to install a sludge cake handling system within the reduced footprint . Upon consultation , SEEPEX ’ s
Smart Air Injection ( SAI ) was selected : a highly efficient system involving a progressive cavity pump and pneumatic dense phase conveying technology , able to transport 16-40 % DS dewatered sludge with a significantly lower operating pressure requirement .
SAI technology is an energy efficient solution for long distance pumping , proven to significantly reduce operational and total investment costs
84 PECM Issue 55