Pulp and Paper

The annual consumption of paper per capita in industrial nations is approximately 200 – 250 kg. The global average consumption of 54 kg per capita and year is still far behind.

About 20% of the world’s harvested wood is used for the production of Pulp and Paper, although today recovered paper supplies 40% of the fiber raw material.

The increasing market and challenges arising with respect to energy efficiency and environmental protection require new technologies and optimized processes in the pulp and paper production.

bionic surface technologies features experience in the industry as well as proven concepts from more than 200 successful projects, which can bring the key advantage.

The complex process of papermaking can be analyzed and optimized by up-to-date CFD simulations.Cost and time for prototyping and test series can be massively reduced.

Desired objectives can be achieved efficiently and reliably!

Simulations for the production of pulp and paper

• The pulp and paper mixture is modelled as a non-newton´s fluid.
• bionic surface technologies has different calculation models available depending on the composure.
• In the graph, three models are presented.

Headbox

Simulation and result analysis

• Examination of air accumulations for quality optimization of the head box
• Suggested improvements for the optimization of the flow

Optimization and fast trouble shooting

• Existing systems can be used for simulating different optimizations beforehand and therefore crucially reducing the effort of “trial and error”
• Fast trouble shooting is possible with different input parameters

Examination of possible air accumulations

Examination of the occurence of fiber shafts

Suction Box

Drainage

• The calculation domain consists of three zones: pulp, sieve, ceramic
• The sieve and the pulp are dragged over the ceramic.
• In the sieve the same volume fraction of water is set.

2D model with high-resolution sieve (2 phase model) ~30µm gap

• Water distribution in the sieve and the fiber mat

Press

Press

• The calculation domain consists of the following zones: 2x press, felt, paper web.
• The water is pressed out of the paper web into the felt and depending on the configuration the water is being skidded away or sucked away.
• The goal is to remove as much water as possible from the paper web.

Model press roll: velocity and water transport

Model vacuum supported perforated roll: water distribution in the sieve and in the fiber mat

Drying cylinder

Drying cylinder

• The calculation domain consists of the following zones: internal space of the drying cylinder, cylinder wall and paper web
• Hot steam is being condensed on the wall of the drying cylinder and emits heat, which is used for the drying of the paper web
• The goal is evenness and a good removal of the condensate as well as a high heat transport from the inner wall of the drying cylinder to the paper web

Analysis of the flow for the optimization of a drying cylinder

• Sucking of the condensate phase (red) through steam (blue)
• The condensate is pressed through the pipe because of the overpressure in the cylinder

Analysis of the flow for the optimization of a drying cylinder

• Evaluation of different suction concepts concerning heat flow.
• The condensing steam emits heat which is emitted at the wall of the cylinder.
• The heat conduces the drying of the paper web.

Pressure screen

In the pulp and paper industry pressure screens are used to guarantee that no contamination is transported further in the system.

Analysis of the flow for the optimization of a pressure screen

• ~ 3 millions of cells with a block structured network construction from the rotor to the rings
• Different building techniques are compared and optimized regarding their efficiency
• CFD analysis for increasing the specific output and the service life
• Examination of the dead water zones