Bluebell Pumping Station
Dublin City Council came to DPS with their most troublesome sewage pumping station in the Bluebell section of the city. In place were 3 competitor’s submersible pumps in a D/D/S arrangement. One or more pumps blocked at least once a week. Not only did the Council want replacement pumps that did not block as frequently, they also wanted to increase the flow rate out of the sump to compensate for the future increase of effluent into the sump.
During a thorough site visit, DPS’s technical manager gathered information on the existing pumps and performance, the size of the sump, inflow into the sump and the size and length of the pipe-work. Using this information to calculate a system curve and duty curve and based on his extensive experience, he was able to offer the Council a remedy to their problem. This included 3 new KSB pumps with an improved better impeller type (Vortex) compared with the competitor’s existing single channel impeller and an increased solids handling capacity (100mm versus 76mm). Furthermore, the KSB selection would provide for an increase in flow rate as the Council wanted. Based on further calculations by the DPS Technical Manager, we were able to confirm that if the Council increased the pipe-size out of the sump to the main drain pipe by a few inches they could increase their flow rate by 65% and thus be confident of being able to meet future requirements.
In addition, because DPS were able to provide a flange adaptor to enable the KSB pumps to fit onto the existing competitor’s guide rail adaptor (claw) there was no need to change the existing guide rails or the duck-foot bends (pedestals) in the sump. The Council ordered the pumps, accepted our recommendaions and increased the pipe size running out of the sump. In the 5 years since their installation, the KSB pumps have never blocked and the Council is more than happy with the flow rate.