The pumping stations in particular can be used for pumping industrial wastewater with a high microbiological risk, due to the fact that it is a hermetic device and the staff does not have direct contact with the pumped medium, however the possibility of making the device from acid-resistant steel (additionally subjected to the process of passivation through electro-polishing) makes the entire installation immune to a number of inconveniences related to the chemical composition of the wastewater. In addition, the cyclic nature of the operation and short time of keeping the wastewater in the tank reduces the risk of their rotting. The use of pre-separation, limits the contact of the pump with solid and long-fibered elements, which reduces the risk of clogging the pump impeller. However, it should be remembered that maintaining the correct conditions for self-cleaning of the separator requires cyclic operation and to ensure the proper ratio of liquids to solids in the wastewater for this reason, the selection of the device must be made by qualified engineers.

Due to the chemical composition, physical properties or content of abrasive elements, it may be necessary to make pump flow systems in both pumping stations and classic pumping stations from materials with higher resistance than gray cast iron commonly used in municipal wastewater pumping stations (application in the range: 6'pH'8, negligible amounts of chlorides and abrasive elements below 0.5g/l).

However, the common denominator in classic pumping stations and the guarantee of correct operation in all conditions is the design of the of the pump's flow system. This is particularly evident in the impeller's resistance to clogging with fibrous bodies, which tend to wrap and wedge at the inlets of the impeller blades. In this regard, pump manufacturers use two strategies:

• Grind - the use of cutting knives or grinding rotors,
• Avoid blockage - use of large free vias, small number of blades, vortex type rotors.

A combination of both of the above is the new generation of FZF-type rotors. These impellers combine the advantages of ducted impellers of high efficiency with the operational reliability of open impellers with large throughputs and the ability to split fibrous bodies. Their main characteristic feature is the spun and receded in the center edge of the inlet edge of the blade. This causes the fibrous bodies to slide to the center of the blade where there is a high speed of flow, and the spun edge further facilitates the body's slide into the rotor.

In addition, the rotor inlet features an enlarged free passage that reduces the risk of blockage, and in the event of its occurrence, the blockage elements are shredded through the blades of the semi-open rotor working together with a highly hardened disc with a grinding groove.

Combining the best features to facilitate the pumping of fibrous bodies along with high efficiency, thanks to optimization of the flow system using numerical fluid mechanics methods CFD fluid mechanics methods and the use of high-quality materials to extend service life in harsh environments operation makes it a good compromise between functionality, energy consumption and price. Not without significance is also the cost of operation, which is minimized here through the use of a highly hard and adjustable cutting disc, which allows easy restoration of nominal parameters even after the gap between the rotor and disc due to pumping of abrasive wastewater.

Due to the use of two blades, which evenly will wear over many years of operation, FZF pumps maintain a stable dynamic state and provide the possibility of good impeller balancing, which is not easy to achieve for single-vane impellers.



Feel free to contact us:
Technical Advisors