ACE were invited to take a look around the pumping station. ACE quickly spotted an option which could work, the option was modelled by their partners, Pentair Nijhuis using their in house CFD software. The CFD models showed the solution worked and ACE had an option which enabled exactly what the customer required, a fish-friendly submersible pump which would not require alteration to the pumping station forebay.
An archimedean revolution- Fish Friendly Screw Pumps
The concept of an Archimedean screw is over 2000 years old, and has many uses in modern life, however it is commonly used in a trough for moving water. This often makes the cost of their use prohibitive, due to complicated construction and restrictions on size. Along with this, wear levels are high, and leakage down the screw can reduce their efficiency,
meaning larger sizes are specified to achieve the desired result.
Fish Flow Innovations have revolutionised the use of Archimedean Screws by being loyal to the original concept of using the screw in an enclosed tube- this way every drop that enters the screw is moved to the top, vastly improving efficiency, with obvious knock-ons to running costs, reducing size of the pump, and even savings in construction of the surrounding buildings and civil structure.
The design is simple, yet very clever, using high grade materials such as Stainless Steel and Vinyl Ester Composite to keep weight low, preventing osmosis-related damage and ensuring a long, trouble free life. A major factor in it’s efficiency is that there is no leak path, with no requirement for seals that can wear on the screw vanes, meaning that EVERY drop that goes in, is pushed out at the top.
The pump is delivered as a single module, can be installed in a matter of a few hours, and requires an extremely simple civil structure, vastly reducing site costs when compared with a traditional screw pump.
Unrivalled fish friendliness
The ACE archimedean screw pump has been developed in the Netherlands by Fish Flow Innovations, with the key design criteria being absolute safe passage for fish that enter the pump. In developing a specifically designed leading edge for the pump, benefits in efficiency and energy savings were also noted, making the pump the perfect solution.
The leading edge has a curved vane, which glides smoothly into the water to reduce splash and turbulence, and in turn it hydraulically guides fish and debris into the screw pump preventing collision. The smooth entry into the water also prevents direct strike as found with common screw designs, and the lower speed that is required due to the increased efficiency also helps to preserve fish in the area. The pump has an in-built reverse facility that on stopping the pump, it is allowed to back-wind for sufficient rotations to empty the pump prior to applying the brake, allowing any aquatic life that remain in the pump to escape.