Cas d’application
Sewage Interceptor and Pumping System for Quarteira and Vilamoura
If the Algarve is considered to be Portugal's major tourist region, then Vilamoura is where tourism reaches the pinnacle of excellence, boasting as it does the most complete and varied tourist facilities in Europe. Not only does it have an agreeable climate and natural beauty, but also the development of tourism is guaranteed by the quality of its infrastructures, landscaping, easy access, hotel complexes, self-catering units and sport & leisure facilities such as the marina and prestigious golf courses.
The Situation
In this context, the Multimunicipal Sanitation System for the Algarve, managed by Algarve Water (Águas do Algarve), is of extreme importance as it ensures the maintenance of the high quality of the environment and the sustainable development of Vilamoura and also Quarteira. By accepting the Contract to Implement the Interceptor System for Quarteira and Vilamoura, Algarve Water took on responsibility for the collection and treatment of domestic waste water for a population that exceeds 190,000, at a cost of 5,215,000 Euros, 56% of which is from the Cohesion Fund.
The Grundfos Solution
The heart of this interceptor system consists of three pumping stations: the EE CE3 (Vilamoura), the EE CE2 (Quarteira) and the EE CE4 (Fonte Santa). The first two were redesigned from the existing pumping stations, while the third is an entirely new station.Therefore, implementation of EE CE3 and EE CE2 was more complicated, since during the time that the old equipment was deactivated and the new equipment was installed it was essential that the collection and pumping of waste water continued without any interruption, and in an environmentally responsible manner. The system works as follows: the stations in Quarteira and Fonte Santa pump the waste water to a common interceptor, from where it is conveyed to the Vilamoura station, which also receives waste water from its own installations. The final destination is the Vilamoura Waste Water Treatment Plant, which was also renovated in June 2006. To meet the project specifications, and during the summer season, the Vilamoura pumps are rated for a peak flow of 950 l/s.
The Outcome
The EE CE3 became fully functional in September 2006 and the EE CE2 in November 2006. The photographs on the right show the EE CE2 as well as the different ways in which the current and the old electric pumps function. The old pumps had a vertical axle, with the electric motor on a higher level and a transmission shaft that drove the pump on a lower level, at the same level as the wet well. For the current installation, the project opted to specify single stage submersible pumps, with a cooling jacket, allowing them to function in a vertical position, and under dry well conditions. The pumps are installed on the lower level, while the upper level is used for the collector and access chamber. In addition to increased capacity and efficiency, the new Grundfos systems provide other advantages such as greater reliability and easier maintenance. Throughout the tender process, the pumps from Grundfos Environment Finland proved to be the best choice for this particular application. Not only did they fulfil the layout specified in the project, but also the hydraulic characteristics of the pumps were shown to have the required flexibility. For example, the S2-654-BM3 pumps for the Vilamoura pumping station lifted 260 l/s with a single pump, and up to 950 l/s with four pumps in parallel; the differences in the flow rate mean that, in terms of total manometric height, heights vary between 11 and 21 MCA. A series of hydraulic simulations were carried out, comparing the different performance curves of the system with the curves of the pumps in parallel, which demonstrated the suitability of the Grundfos submersible pumps. The flexibility of the system is further guaranteed with frequency converters, which regulate all of the pumps. In addition to their excellent hydraulic characteristics, the Grundfos submersible pumps used for continuous heavy work have other characteristics, which include: a cooling jacket to cool the motor under dry well conditions, the passage of solids with diameter between 80mm and 100mm, humidity control in the oil chamber, temperature control in the windings and bearings, a humidity sensor at the cable entry point and an impeller clearance adjustment system (SmarTrim) to ensure that the original efficiency is maintained over time. Together with the main electric pumps, Grundfos has also provided the latest AMD range of agitators, built entirely of stainless steel. All of the pumping stations have two wet wells, which are interconnected; an agitator is installed in both of them to stir the waste water, preventing sedimentation of solids and increasing the reliability of the pumps. The project was designed by Profluidos, with Planege being responsible for supervising the work.
The construction was awarded to the Somague-Neopul-Engigás consortium. Installation of all the electromechanical equipment was the responsibility of Engigás.