“The inadequate capacity of our disc filters was triggering us significant issues. They ended up A really troublesome bottleneck and the complete system was negatively influenced – acquiring the proper solution was a necessity,” claims Patrik Jansson, Functions Engineer at Holmen’s mill in Hallsta, Sweden. “We have been originally skeptical that a corrugated filter bag may be the solution, but since the thought of purchasing new, pricey disc filters was not everything beautiful, we chose to give Valmet’s WavStar filter luggage a test. The choice, with sectors in corrugated metal instead of filter luggage, was not an alternative for us both. The references we checked out confirmed that it was hard to achieve the promised ability, and even In case the assistance life of plates is for a longer time than for filter bags, the price of expense is higher. “Using corrugated filter bags was a completely new point for us, and we questioned just how long the filter bags would very last. But simply because Valmet promised a services life of not less than a few years, we felt safe in transferring forward with our conclusion, Regardless of a couple of misgivings.”
Stable capability improve
“Since we’ve evaluated the outcomes after the filters are already functioning for a lot more than two several years, we can easily see the advantages and we understand that the main benefit is during the enhanced ability, meaning we don’t have to speculate in more filters,” states Patrik Jansson. “The corrugated cloth drastically improves the sector’s area area, which clarifies why dewatering is now a great deal of more effective. “The numbers deliver a clear information. For the reason that installation, we’ve been able to extend capability from to one,tonnes each day – a twenty p.c rise – that has been steady all over the time we’ve been using the filter baggage. A part of the increase is because of us shifting the cleaning and cake discharge shower procedure and obtaining a little bit superior at caring for our disc filters. However, the main reason is The brand new filter baggage.”
“A different constructive influence would be that the nozzles usually do not get clogged,” Patrik Jansson carries on. “In the high speeds we were operating at in advance of, this was a big trouble. Large speeds also develop lousy, fabricsystems slender pulp cakes. Contrary to what just one may believe, it’s a benefit to be able to run in a reduced pace, mainly because it is hard to have the pulp to sort a superb cake at larger speeds. We’ve been able to lessen the pace from 1.eight to one rpm, which is good – the filtering is nice along with the fibers have time to make up right into a cake with the proper dampness content and thickness. Considering that the cake is thicker than in advance of, the filters are cleaner.
“Valmet installed the main filter as Portion of the extensive assistance, but given that then we’ve changed them ourselves. One variation from just before is always that we now adjust all sectors and fabrics concurrently. In advance of, we consistently experienced terrible fabrics that needed to be frequently changed. Identifying which sectors had to get replaced was time-consuming when you consider that we experienced sectors to observe.”
Examination – an support in support
“Typical disc filter upkeep is performed during the autumn,” claims Patrik Jansson. “Just one sector is taken down and samples are despatched to Valmet for analysis. This tells us exactly how much power continues to be during the weave and can even reveal the expected service lifetime, which happens to be useful. The Investigation also consists of specialized operation conversations. We really take pleasure in the technical assist we get from Antti Mäkinen at Valmet. Both equally routine maintenance and repair became easier.”
“With WavStar filter luggage, the bottleneck was removed,” Patrik Jansson concludes. “Dewatering for that disc filters is currently properly dimensioned, the method is optimized plus the filter bags work very well – we’re really happy with the final results!” The demands put on paper and board equipment apparel are higher, as being the fabrics really need to assistance The sleek operation of the whole manufacturing line. Dryer fabrics also need to have to face up to significant temperatures, high cloth use possibility caused by mechanical seals and rolls, along with higher-pressure cleansing around bars. Valmet Dryer Cloth OR for single felted groups (earlier referred to as OptiRunner) was developed with modern drying sections and gadgets in your mind. “It’s got a sensible double warp procedure to enhance effectiveness and save additional Vitality in Probably the most Electrical power-intensive programs of the paper device,” points out Juha Paavolainen, Product Manager for Forming and Dryer Fabrics at Valmet.
A durable double warp procedure
While in the drying section, mechanical seals are put ten mm from the fabric, bringing about an important hazard of abrasion. Present day seals are a significant Electricity-conserving aspect, Nonetheless they require additional long lasting dryer fabrics. “Durability has become the cornerstone of Valmet Dryer Fabric OR enhancement. Its intelligent structure will work in harmony with contemporary blow bins, and we’ve been able to provide extra energy cost savings and enhanced runnability to our prospects,” states Paavolainen.