HiCon 2.0 in practice: Mpact benefits from increased capacity and reduced energy requirements
South African paper manufacturer Mpact is the first of Voith's customers to use an InfiltraDiscfilter with HiCon 2.0 technology following a machine rebuild. At Mpact, the disc filters have significantly exceeded expectations.
Efficiency and responsible use of resources are the two key requirements that papermakers demand of modern paper manufacturing. With HiCon 2.0 technology for InfiltraDiscfilters, Voith's customers gain an important variable allowing them to pave the way to meeting these criteria as early as the stock preparation stage.
The new technology from Voith's BlueLine range is the latest development of the disc filters, which began in 2012 with the launch of the BaglessPlus system and was followed by the HiCon technology in 2014. This new system not only allows the consistency of the stock flow in the inlet to be increased but also raises throughput by up to 20 percent. Filters fitted with HiCon have already demonstrated in a large number of applications in both new builds and upgrades that they are robust enough to readily handle high and strongly fluctuating stock consistencies in the inlet.
The HiCon 2.0 technology builds on these proven concepts but has added two crucial innovations: Firstly, a sturdy system ensures stay on track, which helps prevent damage to the filter. And secondly, because each disc is fed separately, the flow pattern in the vat can be reversed, which prevents thickening of the pulp. In conventional disc filters, higher inlet stock consistencies inevitably result in a high degree of thickening in the filter vat. This is why most paper manufacturers dilute the stock flow upstream of the disc filters. This means higher water input and a higher demand of pumping energy.
The HiCon 2.0 discs render the energy- and resource-intensive dilution process upstream of the disc filters unnecessary. As the technology substantially reduces vat thickening, the use of HiCon 2.0 allows inlet stock consistencies of up to two percent, compared with the one percent that is standard for conventional technology. The existing thickening capacity limits maximal possible production in older stock preparation plants. By eliminating this bottleneck with HiCon 2.0-Discfilters in the stock preparation phase, capacity increases of up to 20 percent are possible.
The use of InfiltraDiscfilters with HiCon 2.0 technology also offers potential for saving maintenance costs, because unlike conventional systems, the maintenance and monitoring effort is minimized. One reason for this is that the filter discs do not have filter bags, so there is no need for time-consuming and costly replacement of used filter bags.
The premiere of HiCon 2.0 technology at the South African board and corrugated cardboard producer Mpact has shown that this potential is not just possible in the laboratory but can also be realized in practice. As part of a restructuring of the company's paper mill in Felixton to make production ''greener'', recovered paper fibers have been used instead of the sugar cane waste product bagasse since 2015. A machine rebuild was designed to increase the machine speed from 700 to 930 meters per minute, to achieve the goal of a 40 percent increase in production. For this project Voith executed an upgrade of the complete stock preparation unit. Since the completion of the rebuild in 2016, a vertical LC pulper with a capacity of 800 metric tons per day has been added to the existing drum pulper. The new system incorporates InfiltraDiscfilters with HiCon 2.0 technology. Maggy Odayar, Technical Manager at Mpact, describes the results: "The disc filters have proven to be reliable, efficient and highly flexible in respect of inlet stock consistency and stock flow. Throughput is 15 percent higher than the planned rate.” Long-term tests show that consistencies of two percent can be sustained. The filters installed at Mpact can also readily handle consistency peaks of 2.5 percent. The upgrade of the components was an important element for increasing productivity of the entire system.