The new online L&W Pulp Tester is a complete wet laboratory with automatic sampling from different positions along the process chain. Repeatable tests are made automatically and frequently. By keeping product quality on target from online measurement of the quality parameters it is possible to optimize the process settings and adjust the target values closer to the quality limits. This minimizes the operational costs.
L&W Pulp Tester
The online L&W Pulp Tester consists of automatic standard and established tests for CSF, SR, brightness, color, fibre length, kink etc. suitable for building up an automatic quality monitoring and optimization system in the mill. The true variations in the pulp quality parameters are monitored in real time and are used to secure product quality, save time, material and energy, and increase production. Here are a few examples;
Save energy and fibres
Energy is the dominating cost in mechanical pulping. Lower energy consumption means direct savings. Here is an example of improved control of freeness based on automatic online measurements in accordance with Canadian Standard Freeness (CSF). Suppose the production rate is 66 000 ton annually and the power cost is 60 euro per MWh. Decreased over-refining from 160 ml CSF to 176 ml will save 50 kWh of electric energy per ton pulp. This corresponds to savings of 198 000 euro every year. The calculation is based on a reduction of variations in CSF from 15 % to 5 %. Earnings in the next step from delivery of more uniform pulp to the paper machine are not included. Such an additional saving can be less reinforcement pulp.
In production of bleached chemical pulp a similar example can be calculated for improved bleaching control based on measurement of standard ISO Brightness. If we in this case have a production rate of 330 000 ton per year and an ISO Brightness of 90 %, then decreased over-bleaching with 0.3 % (Brightness value) will save 4 % chemicals (ClO2), which corresponds to savings of 195 000 € for hardwood (the corresponding number for softwood is 244 000 €) every year.
Improved freeness control can also be applied on beating of chemical pulp in the paper mill. For example, if the paper machine is drainage limited, more uniform refining admits less refining and better drainage Then control of CSF or SR generates a speed increase of 0.5 % generating savings of 225 000 € per year from increased production. In this calculation the production rate was 150 000 ton per year and the value added over the paper machine was 300 euro per ton. Energy savings are additional.
These kinds of improvements motivate investment in L&W Pulp Tester. Improved monitoring and controlwill also help to avoid breaks and drift off from quality targets and many other savings are also possible.The actual situation is unique for every mill but clearly, better monitoring of quality creates possibility for optimization and cost savings in every mill.