Magdrive and mechanical seal industrial pumps
Horizontal and vertical centrifugal pumps

Demin-water is commonly required for several applications in industrial plants and it's production facilities are often built directly on site. One of the typical pump applications in the Demin-water production process consists in injecting small quantities of NaOH or HCl in an intermittent service.

When required flow-rates are small (0.5-3 m3/h) and are combined with relatively high discharge heads (40-70 meters), the selection of a suitable pump is not an easy task, especially if both duties - NaOH and HCl - have to be achieved by the same pump model. Standard pump options are usually either multistage or dosing diaphragm pumps. Both options however present several disadvantages that can be successfully solved by magnetic driven peripheral turbine pumps in plastic.

CDR Pompe has successfully installed several HTN mag-drive PP turbine pumps in the Demin-water production facility of a Belgian steel manufacturer. The customer was previously using multistage mechanical seal pumps with the inconvenience of NaOH typically damaging the mechanical seal. In fact, NaOH tends to crystallise in contact with air and tends to heavily deposit around the seal area compromising the functioning of the mechanical seal. Trials were made both with single and with double seal options with no major improvements. Being an intermittent service (approx. working time is 1 hour/day), problems with crystals clogging the seal area were worse. As a consequence, the short life time of the mechanical seals (they were failing approx. every 3 / 4 months) generated high maintenance costs combined with plant down-time periods.
In an attempt to bypass the seal problem, the customer replaced the multistage pumps with dosing diaphragm pumps. However, he was then having troubles due to pulsations combined with higher purchasing costs and increased maintenance costs due to the wear of expensive components.

He finally found a solution installing CDR Pompe magnetic driven peripheral turbine pumps HTN in PP: purchasing cost is relatively low, same pump model can be used both for NaOH and HCl (thus standardising pumps and spares), maintenance intervals and costs are kept low thanks to the magnetic coupling, that prevents any contact of the caustic with air, thus eliminating the crystallisation problems; last but not least, regular, pulsation free flow-rates are achieved.

The pumps have now been working for over 12 months without requiring any maintenance whatsoever.
Further, thanks to their compact design, they could be installed very easily.