Valmet will supply an upgrade of the evaporation plant at Södra Cell's Mönsterås pulp mill in Sweden. The upgrade will unload the capacity of the existing evaporation line No. 1 and improve steam economy by increasing the capacity of the existing evaporation line No. 2. The delivery is scheduled for autumn 2016.

The evaporation plant concentrates black liquor coming from the digester in a mill. In the evaporation process, the evaporated water is brought back to the pulp production process to minimize mill's water consumption. After evaporation, the concentrated black liquor is fired in the recovery boiler for steam generation and recovery of cooking chemicals.

The new Valmet equipment to be installed will be two tube evaporators, a falling-film reflux condenser and four liquor preheaters. A substantial upgrade of the piping system and an integration and upgrade of an existing condensate treatment system also will be performed.

The new order follows a similar evaporation plant upgrade of the Södra Cell, Värö mill, which was awarded to Valmet last year, together with upgrades of most process areas in the same mill.

"We are looking forward to this project and are satisfied with the technical concept Valmet has offered us. This will improve the function of the evaporation plant, increase the energy efficiency and increase our profit," says Jonas Olander, project leader at Södra Cell Mönsterås.

"We see this evaporator upgrade bringing many benefits for Mönsterås mill. Besides improving the steam economy of the plant, we are implementing dry solids content control of the firing liquor to the recovery boiler. We will also add additional washing possibility of existing heating surface areas to improve plant availability," says Fredrik Vedin, product sales manager for evaporators at Valmet.

Over the years Valmet has assisted Mönsterås mill by making several smaller and larger upgrades of the existing evaporators. The co-operation started in 2001 when Valmet replaced damaged lamellas with its Tubel and also installed a new Tubel Super Concentrator.