Our largest medium-consistency pump

In March 2013, ANDRITZ got the order to deliver six pumps for conveying medium-consistency pulp at a capacity of 4,400 admt/d. The new pulp line will feed a new washer which is designed for 7% consistency. For this capacity and this consistency, very large pumps are needed – actually the largest medium-consistency pumps ANDRITZ has built so far. Generally, ANDRITZ medium-consistency pumps can convey stock with consistencies of up to 16%, if the subsequent equipment supports that. 

One reason why ANDRITZ received this order was the short delivery time of only 4 ½ months. Manufacturing was so fast that there was also time for a full range test at the ANDRITZ pump test center in Graz. There an efficiency of 74% (BOP) at a consistency of 8% was reached, which is far above the industry average and the best efficiency ever achieved with a medium-consistency pump. The maximum efficiency obtained in a commercially available system so far was below 70%. The pump runs extremely smoothly with the characteristic curve not showing any discontinuity. It was also tested at a consistency of 12%, then reaching a capacity of 2,000 m³/h, which is equivalent to 7,200 admt/d.

Like all ANDRITZ medium-consistency pumps, the MC 300-660 is equipped with the innovative SMARTSEP system. With this system, the air is removed from the pulp suspension and transferred to the degassing line by a specially designed separation impeller, while at the same time any fibers removed with the air are returned safely to the pump, guaranteeing that there is no fiber loss. Control of the degassing valve is simple: pump running – valve open; pump not running – valve closed.

At one of the world’s largest single pulp lines, the UPM pulp line in Fray Bentos, Uruguay, energy savings of 7 to 15% were achieved with the new ANDRITZ medium-consistency pump in comparison to a competitor’s pump formerly installed there. Control of the pump was highly simplified by using SMARTSEP. There have neither been problems with degassing, nor any fiber losses since the start-up in November 2010.

At the Mondi Syktyvkar mill in Russia, new-generation ANDRITZ medium-consistency pumps were installed in the course of mill modernization. A major challenge was to integrate the new equipment into the existing plant and make it all work. “The ANDRITZ medium-consistency pump, with its easy handling, really contributed to a successful start-up,” confirms Mika Makela, Project Manager for the Mondi Syktyvkar Step Fiberline Project at ANDRITZ.

In the Fibria Jacareí pulp plant, Brazil, an existing medium-consistency pump was replaced by an ANDRITZ medium-consistency pump. In spite of the higher pumping capacity, the existing motor could still be used. This gave the customer energy cost savings of over one-third.