PECM Issue 21 2016 | Page 105

Physical and chemical erosion of the Once the trough has been trough increases the gap between the properly prepared, fresh concrete outer edge of the screw pump flight and is poured and a new trough starts the trough itself, which allows more water to take shape. The finished surface to pass the flight rather than travel up the is created by reinstalling the screw trough. which has temporary screeding bars attached to the flights and This will clearly affect the overall efficiency slowly rotating the screw to give of the screw pump as more energy will be the perfect clearance. required to transport the same volume of water.Although this is a very gradual While the flights on the screw process there comes a point where the were refurbished the bearings increased energy costs and reduced can also be replaced and in cases performance necessitate a refurbishment where the bottom bearing has a forced of the screw and trough. lubrication feed, this can be replaced with a new stainless steel, eco-friendly bearing In essence this involves welding a new which is sealed for life and requires no section onto the flights of the screw annual maintenance. Top bearings can be pump to return the outside diameter to assessed for wear and replaced as required its original dimensions and then remaking to ensure the refurbished installation will the trough to provide the optimum flight continue to operate for many years to to trough clearance. come. Having removed the screw for refurbishment, the on-site team would expect to break out the original concrete trough using a pneumatic breaker that is fitted to a remote controlled, tracked vehicle. ECS Engineering Services is able to offer an on-site inspection service, carried out by experienced engineers to assess the condition and expected lifetime of any screw pump installation. If any maintenance is required, ECS can Due to the access difficulties involved deliver a complete service offering, with refurbishing the concrete trough it including, if necessary, renewal of the is important to carry out the work in the screw itself with support from its long safest manner possible. established partner Landustrie. This type of project is something that ECS Engineering Services is regularly involved with, providing a complete turnkey solution that minimises any disruption to the operation of the treatment works. www.ecsengineeringservices.com