The replacement of electrically driven diaphragm pumps and their adjustable gearboxes, has proved a great success at Langsett Water Treatment Works. Two VERDERFLEX VF40 peristaltic pumps with in-built inverter control were installed by Staptina Engineering Services to dose a lime slurry. The diaphragm pumps previously used to perform this duty required a high level of maintenance caused by abrasive wear and the blocking of non-return valves. The new units have no valves, glands or seals and abrasive media has little wearing effect on the pumps. As a consequence, they have run maintenance-free since installation ten months ago.
The original pumps were controlled by a common inverter with servo adjustment on the gearboxes. This dual control method has been replaced by one signal to the in-built inverter on the VERDERFLEX pumps, allowing immediate response to all changes in dosing requirements. The new method allows greater flexibility and fewer mechanical components are used.
Two VERDERFLEX VF50 units have also been installed at the site to replace pumps used in the lime mixing process. Previously, progressive cavity pumps were used, but, in common with the diaphragm units, these required regular maintenance, as they were subject to gland leakage and rotor and stator wear. The new pumps run at a fixed speed and, like the VF 40's, have operated maintenance-free since installation.
For more information visit: www.verderflex.com