Stormscreens and pumps for Spanish wastewater plant

Manchester, UK - Stormscreens and pumps from Mono NOV have been specified for the Upper-Middle Arroyo Culebro (UMAC) Wastewater Treatment plant in Spain, the largest facility of its type in Europe. Through its Spanish distributor, Albosa, Mono has supplied 32 stormscreens and 46 progressing cavity pumps to the UMAC Wastewater Treatment plant, which was designed to handle a maximum flow of 129,600m3 per day.

The stormscreens, which offer an alternative to conventional mesh and powered screens for handling storm overflows, have been installed to ensure that no contaminated solids are washed down into the river during times of heavy rainfall.  They were specified because they are self cleaning, offer low whole-life costs, are self powered and continue to operate in the event of a disruption in electrical power, said Sara Modrego, assistant manager at Albosa.

Each of the stormscreens’s mesh drums incorporates two arms, fitted with adjustable brushes. As wastewater flows into the channel and upwards through the unit, solids above 15mm are captured on the mesh. The screened flow powers a paddle wheel, which is mounted below and behind the mesh drum. This drives a brush wheel which subsequently cleans the mesh drum, returning trapped solids back into the main flow for treatment. An integrated scumboard protrudes into the main flow and deflects large floating solids away from the screen, increasing the screens’ self-cleaning capability.

The stormscreen has a modular construction that is adaptable to existing civil works, with a range of diameters and length options to suit different overflow weir configurations. An optional data monitoring system is also available that incorporates status reports and event logging capabilities.

In addition to the stormscreens, each with a length of 2m and 15mm screening aperture size, the UMAC plant also contains four Mono Widethroat pumps and 42 progressing cavity pumps. These pumps transfer sludge generated from 15 kilometers of collection channels in the southern districts of Madrid, which the plant serves. They are installed to pump the sludge after it has been through the de-watering and sludge thickening process.