Delivering aggressive paper base materials reliably
Generally, the paper industry has to deal less with viscous than with corrosive or aggressive media. This concerns especially the different materials required to turn the simple cellulose sheets into high-grade writing paper.
For example, fillers such as Kaolin or precipitated calcium carbonate (CaCO3), also known as PCC, are added in production to whiten the material.
The CaCO3 sludge generated during production is actually unproblematic to pump at only 500 to 1,000 mPas and a solids content of roughly 17 percent, however, the compound attacks the components in contact with the medium.
In addition to components from corrosion-resistant stainless steel, NETZSCH – for a PCC manufacturer – also used double-acting mechanical seals with quenching supply ensuring stable running and guaranteeing a reliable seal. The material of the sliding surfaces is an extremely robust tungsten carbide nickel combination. With this – and with the special delivery properties of progressing cavity pumps – no spare parts were required for the first 14,400 operating hours. The manufacturer thereby not only saved costs for spare parts but also on production disruptions and downtimes as well as on service staff.