PUMPS MAXIMISING THP PRODUCTION
SEEPEX
Maximise Thermal Hydrolysis Production with Correct Pump
According to government sources , there are 7,078 sewage treatment works ( STW ) in England and Wales , and 10,814 STW in Scotland and Northern Ireland . Pumping and storing sludge cake during the wastewater treatment process can be costly , driving water companies to technologies that reduce their volume to minimise such costs .
This can be achieved through conventional Anaerobic Digestion ( AD ) or through Advanced Anaerobic Digestion ( ADD ) processes , such as Thermal Hydrolysis Process ( THP ). ADD can reduce the volume of solids and increase the yield of biogas used to power engines . This can make plants energy self-sufficient or generate income by exporting power to the National Grid .
ANGLIAN WATER ’ S COTTON VALLEY
At Cotton Valley Sludge Treatment Centre ( STC ), one of Anglian Water ’ s ten main STCs , competitor ’ s progressive cavity pumps were installed to back mix the dewatered sludge and pump it into the THP . The two pumps were costing overall circa £ 100K per annum due to rotor and stator changes every 3-6 months .
Their inability to transfer no more than 3.5m3 / h ( bottleneck and limiting biogas production ) meant the site was not able to meet the design criteria limiting the amount of imported raw cake being handled to only 120 tonnes per day . Additionally , before pump maintenance could be carried out , the silo had to be emptied . This also meant cake imports from satellite sites had to be diverted , which resulted in substantial logistical costs .
SEEPEX supplied and installed two custom-made
open hopper pumps with a dimensionally identical hopper to fit within the same footprint of the original pumps whilst delivering over 55 % increased throughput capacity from 3.5m3 / hr to 5.5m3 / hr .
Prior to the installation of the new pumps , Anglian Water was processing approx . 120 tonnes per day of imported sludge cake with both pumps running . With the new pumps installed , the customer is now able to exceed this by 50 % ( from 120 tonnes up to 180 tonnes ) whilst maintaining the same footprint and motor size .
“ Due to the reliability and performance of the new SEEPEX pumps there is an increase in uptime of the cake import
88 PECM Issue 59