The PREROSTAL® and PreroClean™ Prerotation system is a unique, economical, uncomplicated method of automatically adjusting pumping volume to varying inflow rates using a constant speed motor and pump. It combines the screw centrifugal impeller characteristics of a Hidrostal pump with a specially configured vortex inducing chamber around the suction pipe of the pump. The chamber utilizes gravity to impart a fluid spin in the same direction of rotation as the pump impeller, and this spin produces a flow reduction without the necessity of changing pump speed. This method of matching pump outflow to pump station inflow eliminates the need for any electrical equipment such as inverter drives.
In addition the PREROSTAL system is a highly effective sump cleaning system which does not require any additional mechanical or electrical apparatus such as additional controls of mixers or aerators. It is the ideal solution for handling variable flow application with large or troublesome solids.
The PreroClean™ Self Cleaning Sump is a simplified version of the PREROSTAL and is designed for applications where the primary aim is maintaining clean sumps without the need for flow matching. This option works on the same principles as the PREROSTAL but the weir height and tangential channel dimensions are fixed for each pump size allowing these features and the basin to be moulded into a single-piece, simplifying the civil construction
The PREROSTAL system is a proven and cost effective to the Archimedean screw pump system. We have successfully replaced numerous installations around the world!
Please review the following videos to get a better perspective on how the Prerostal concept works. We have found that while a picture may be worth a 1,000 words, a video can show an even more complete understanding of how the Prerostal system works and what benefits it can bring to your pump station. These videos were produced by ‘Sister’ Hidrostal companies.