Polypropylene Vertical Immersion Pumps for Circulation of Battery Electrolyte Solution

Renewable energy comes in many forms and energy storage is becoming one of the most popular. Reducing waste is essential as we become more conscious of the damage fossil fuels are causing to our planet. Storing power for later use is logical and it does not have the draw backs of other forms of renewable energy production, one of the major flaws being inconsistency and fluctuations in energy generation. Storing power and releasing it when needed at peak times allows companies to take advantage of higher revenues when this extra power is required.

The most common form of energy storage is in the form of batteries, however other popular methods include pumped hydro, chemical storage, and thermal storage. Vanadium redox flow battery technology utilises two electrolyte solutions that are pumped into a twin chamber tank via two separate independent flow lines. These positive (anolyte) and negative (catholyte) electrolytes typically contain a chemical solution with sulphuric acid at around 30% concentration.

The chemicals pass through cell stacks and then through a membrane that divides the fluids but also exchanges the negative and positive ions causing a reaction. As vanadium redox batteries are large and bulky, they are typically installed at power plants or electrical grids for grid energy storage.

Requirement for a Small, Reliable Corrosion Resistant Pump

Manufacturers of these systems require reliable and corrosion resistant pumps to circulate the electrolyte and ensure a smooth and consistent exchange of ions. We worked closely with one such manufacturer to provide a long-term solution, they needed a bespoke pump small enough to fit inside the tank and deliver the necessary flow rate but not consume too much power while operating. Certain compromises had to be made to create the right balance, however we were successful by working closely together with their project team to find a solution that satisfied all parties involved.

Selection of our IM Series Vertical Immersion Pumps in Polypropylene

After understanding the maximum allowed power, the required flow rate, and the depth of the chemical tanks, we were able to specify our IM series vertical immersion pumps. These pumps fit inside a tank or sump with the column reaching the bottom and the motor is situated outside of the fluid in a dry area. Designed for chemical applications involving acids or alkalis, we can manufacture this series in either solid block polypropylene or PVDF depending on the chemical compatibility. The solid block casing has no welds like other chemical immersion pumps, this makes it extremely resistant to the strongest of acids and alkalis as there are no weak points on the casing.

We supplied 2 units with various bespoke features to meet the customer’s specific requirements, these included a 600mm column, ISO flange connection, a special baseplate with alternative hole locations and lifting points. In addition to this, we supplied 2 PVC suction strainers with a 2mm mesh to filter out any unwanted solids that may enter the system and damage the pump.