With landmark 300th order, ANDRITZ FibreFlow Drum pulper confirmed as stand-out leader in drum pulping technology

The first FibreFlow drum built, which is still in operation, was designed for tissue stock preparation. Its 60 bdmt-per-day capacity, 2.5-m pulping-zone diameter and 20-m length is dwarfed by the one planned for DS Smith. The pulper destined for Porcari has a design capacity of 1,650 bdmt per day, 4.5-m diameter and length of 50 m. Subsequent orders reflect the industry’s desire for an even higher capacity of more than 3,000 bdmt per day, which means drums of some 60 m in length. It seems that 1,500 bdmt per day is now a baseline for most customers as they seek to optimize efficiency and minimize cost per tonne of processed stock. ANDRITZ is happily on board with this development.

The DS Smith installation illustrates just how far the FibreFlow drum pulper has come since its inventor Frey Sundman tested his theories in his washing machine at home – nearly causing a marital breakdown! Beyond the sheer size and capacity, the fibre source for the installation in Porcari will be mainly old corrugated containers (OCC) along with some mixed papers, board and shavings from new corrugated board. Until around 2008, old newspapers and magazines and mixed office waste were the principal stock used in FibreFlow drum pulpers. Then the digital revolution dramatically reduced the use of printed material, while changes in consumer purchasing habits caused a steep increase in packaging board consumption.

Turning the original proportions of newsprint and magazines to board customers on their head, the FibreFlow drum pulper proved well suited to the new raw material and a large majority of installations are now based on OCC, including DS Smith in Porcari. DS Smith is a leading provider of sustainable, fibre-based packaging worldwide, to which the high fibre strength of OCC is very well suited. The company employs some 34,000 people in 34 countries.

Customers like DS Smith choose FibreFlow technology for its ability to pulp gently to remove coarse contaminants efficiently and maximize fibre yield from the stock.

It is a sign of how far FibreFlow technology has come, that the innovative reject handling system at DS Smith in Porcari will itself be able to handle up to 135 bdmt per day, which is more than twice the entire stock processing capacity of the first drum produced in the 1970s. It is also indicative of the increasing level of rejects which all stock preparation systems have to handle – 20 percent reject levels are quite normal today - and why FibreFlow drum pulper technology is more relevant now than ever. Not only do customers need to handle more challenging raw material, but to adapt to regular changes in the nature of such material. FibreFlow’s flexibility suits this reality perfectly.

Conventional pulpers, with their rotors, cut rejects into small pieces which are harder to manage. The FibreFlow drum is a rotating device consisting of two sections (pulping and screening) which by contrast defiberizes through continuous turnover. The drum is inclined at an angle to keep the fibre source moving forward. Gravity is also harnessed through the pulper’s rotation and this creates the dropping/falling action, gently separating fibre from contaminants, which are rejected continuously and automatically. Wetting, any necessary chemical impregnation and defiberizing takes place in the pulping section while the screening section houses fibre recovery and reject separation. It is a high-consistency system able to yield maximum fibre recovery and high-quality pulp from all kinds of recovered paper including low-grade furnishes and used beverage cartons (UBC).

Like many of the best technological designs, the FibreFlow drum pulper owes much to its simplicity. Compared with the multi-pulper conventional solutions, the single-drum format avoids wire build-ups and removes the need for the wear parts such as rotors and valves which need maintenance and replacement. Since the mid-1990s, FibreFlow drum pulpers have been manufactured from stainless steel, which further enhanced their durability. The result is a stock preparation solution which is exceptional for its low maintenance and operating costs, and high availability.

Simplicity with precision

“There might be beauty in simplicity when it comes to engineering solutions, but FibreFlow owes its performance and reputation to engineering excellence” says Kimmo Vanhala, FibreFlow Drum Product Manager.

“Precision in design, manufacture and installation is the reason FibreFlow drum pulpers give years of reliable service and exceptional performance. Today’s high capacity drums can weigh more than 250 tonnes and it requires highly professional assembly and commissioning to guarantee long-term integrity, functionality and availability. ANDRITZ of course excels in these skills. We are without doubt the world leader in drum pulping.”

Accurate assessment of the process parameters for each installation are fundamental to the success of each project. FibreFlow technology has been subject to continuous improvement over the course of the 300+ installations worldwide during the past few decades, and methods to measure the infeed material have become increasingly sophisticated. With this in mind, DS Smith’s new pulper in Porcari will represent a new benchmark in load monitoring to ensure absolute accuracy in dosing for pulp consistency.

“ANDRITZ harnesses digitization in design and operation to optimize the effectiveness and efficiency of FibreFlow,” says Kimmo Vanhala. “There is no room for guesswork with such a substantial and foundational part of the paper-production value chain.”

The 300^th order landmark is another chapter in a success story. The story of a solution which has evolved with market needs and revolutionised stock preparation at the same time. The worldwide reputation of the FibreFlow drum pulper grows with every satisfied customer.