Evaporator station

It became evident in 2001, that the evaporator operating at full stretch at Kotlas Pulp & Paper Mill (currently, Koryazhma Branch of Ilim Group) would not be able to cope with a long-term workload and that it would be unprofitable to invest money in the permanent repair of the equipment. In 2004, Kotlas PPM announced a tender for an evaporator with a capacity of 600 tons of water per hour in terms of evaporated moisture for evaporation of black liquor from cooking of sulfate pulp. The tender was won by Ahlstrom (Finland). At the moment, it has been succeeded by the Austrian company Andritz.

Implementation of this project will help reduce the share of organic substances in sewage regularly coming to the Biological Treatment Station by more than 3,800 tons. Thus it will minimize pollution of water resources in the Arkhangelsk Oblast, including basins of the rivers Vychegda and Severnaya Dvina.

Installation of the evaporator will contribute to considerable improvement of the environmental situation at the Mill allowing for a significant reduction in power consumption, including gas. This will also provide a practical basis for increase in total pulp production. The new evaporator is primarily needed to ensure evaporation of the total volume of black liquor resulting from increased capacity of Kamyr-1 and Kamyr-2 evaporators.

The station has a complete technological cycle from reception of black liquor to treatment and disposal of by-products appearing in the process of evaporation. All foul-smelling compounds will undergo collection and disposal. That is all gases, which are now simply discarded by the cook room and the evaporator itself, will be returned into the system and burned in the waste-disposal boiler. In a similar way, methanol appearing in the process of condensate cleaning will be burned.

Another vital factor is equipment reliability. The new evaporator requires less expenditures for current maintenance. The evaporator will be run by only two persons per shift.

Technical parameters of the evaporator’s main technological process