Stora Enso achieves new environmental standards by using the Larox green liquor dregs solution

The pressure filter solution supplied by Larox Corporation to Stora Enso’s Fluting Mill power plant in Heinola, Finland, enables the plant to meet the increasingly stringent waste handling requirements in an optimal way.  The Larox C Series Automatic Pressure Filter is also very energy efficient.

The Larox C Series Automatic Pressure Filter delivered for this process is one of the first of this technology supplied in Finland for green liquor dregs filtration.  Larox is the World’s leading innovator of solid/liquid separation solutions.

The Larox C series automatic pressure filter – an optimal solution

The Larox C series automatic pressure filter offers a superb solution to clarified green liquor cake filtration. The filter can be used with or without cake washing, as needed. The residual sodium oxide levels of the filter cake can even remain under 1.0 percent w/w. It can be installed in a green liquor circuit in conjunction with a Scheibler filter on the clarifier overflow as the flowsheet below or as a stand alone unit just for improved dregs recovery as was the case at the Stora Enso Fluting Mill.

The Larox C series automatic pressure filter is designed for chemical processing industries. By utilizing the filter, it is possible to exceed the strict requirements concerning end product quality and uniformity as well as production efficiency, reliability, and safety.

For a long time, Stora Enso’s Heinola Fluting Mill and Larox have cooperated in the development and engineering of the green liquor dregs filtration process. As a result of this cooperation, in 2006, a contract was signed on the delivery of the Larox green liquor pressure filter to the recovery boiler SK 2 plant.  After thorough test filtrations, a precise research project, installation and training campaigns, the filter was commissioned in the summer of 2007.

The personnel of Stora Enso Heinola Fluting Mill are very satisfied with the results. The manager of the power plant, Mr. Erkki Vuori, says that the filter solution can even be considered as a major environmental achievement. ”Due to the drying process in the filter, our dump volume and waste transportation costs have even reduced by 70 percent. The cake moisture has dropped to below 20 %, i.e. the dry solids in the filter cake are now over 80 %, Erkki Vuori reports.

Petteri Taavitsainen, Senior Manager of Sales Support and Deliveries, was responsible for the delivery process of the filtration solution to Heinola Fluting Mill.  He tells that the Larox green liquor dregs pressure filter solution, delivered to Heinola Fluting Mill’s recovery boiler SK 2, went through a thorough test filtration campaign on the mill’s own dregs slurry samples.  As a result of this procedure, the applicability of the solution could be guaranteed.

Heat resistant and easy to use

Mr. Sami Kalmi, Departmental Engineer of the Heinola Fluting mill power plant, says that the sizing of the equipment was precisely correct. Service has reliably provided the specific technical solutions to meet the requirements set by the high temperatures in the power plant. “The green liquor temperature at our power station can be as high as + 90 °C, which is much higher than at our other mills across the world. This sets a great challenge for the lifetime of the rubber parts,” Kalmi says. ”The filter at the power station is in continuous operation, i.e. its availability rate is high. We could not be more satisfied,” Kalmi emphasizes.

Kalmi also praises the Larox pressure filter as very easy to use. ”The highly automated pressure filter is fully automatic in operation and the user friendly control panel is seldom needed.” Kalmi summarises user experiences. ” Operation and maintenance training was thorough, the number of sessions met our needs and the consultation was of good quality” Kalmi adds.

Petteri Taavitsainen confirms: “After sales service is a matter of honor to Larox. Our worldwide and 24 h/d service availability makes Larox a reliable and trustworthy partner.”


Globally desired environmental technology

The Larox pressure filter has been developed to meet the worldwide growing environmental requirements.  ”The Larox pressure filter offers a solution to the current and future challenges of the chemical process industries. We provide advanced technology, based on decades-long experience.  Larox solutions have high worldwide demand and good future market prospects,” Larox Sales Manager for Finland, Mr. Heikki Kupias, summarizes the global situation. ”The Larox C series automatic pressure filter provides higher separation efficiency than any alternative technology. In operation, the filter is energy efficient. It increases the amount of recyclable alkali significantly and reduces the waste transportation volumes to a fraction compared to current technology, not to forget the positive environmental impact” Kupias specifies.

Petteri Taavitsainen adds that cost benefits related to the process’s alkali- and transportation costs can also be achieved: “when alkali is recovered by using the Larox pressure filter, it can be stored and re-used later on in the process.  This reduces total production costs.”

Finland-based Larox Group is one of the world’s top suppliers of solid/liquid separation solutions and services to processing industries. Stora Enso, also based in Finland, has some 44 000 employees in more than 40 countries on five continents. The group is listed in the Helsinki and Stockholm exchanges. Stora Enso is an integrated paper, packaging and forest products company, producing newsprint, magazine paper, fine paper, consumer board, industrial packaging, and wood products.

For more information please contact:
Larox Corporation
P.O. Box 29
53101, Lappeenranta, Finland
Phone +358 207 687 200
Fax  +358 207 687 277
E-mail [email protected]

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