Multistage centrifugal pumps for cardboard manufacture

The cardboard manufacturer de Eendracht situated in Appingedam in Holland has been manufacturing cardboard for over 90 years. The factory produces 70,000 tonnes of grey board and 90,000 tonnes of duplex cardboard; up to 320 metres of cardboard rolling off the conveyors every minute!

The Situation
These days, the main raw material is no longer straw, but recycled paper. The paper is mixed with large quantities of water and pulped using large cutters. This pulp is then transported via conveyor belts over a filter or a sieve to remove the surplus water. In order to prevent the filter becoming blocked, it must be cleaned continuously, which is done using high pressure water jets.
Previously, the traditional submersible pumps were used in order to achieve the required pressure.
However, the system of de Eendracht had a number of drawbacks: high energy consumption, high purchase and maintenance costs and leakages.

The Grundfos Solution
Therefore, the decision was taken to use a Grundfos CRN 16 pump in combination with a Grundfos CRN 16-160/15SF high pressure pump, which is able to supply a pressure of 40 bars.