Treatment of Pulp and Paper Industry Effluent Using New Low Cost Evaporation Technology with Polymeric Heat Transfer Surfaces, 1996 Minimum Effluent Mills Symposium Proceedings

Peter R. Koistinen

Hadwaco Ltd. Oy

A new evaporation technology using high tech polymeric films as heat transfer surface in a Mechanical Vapor Recompression (MVR) evaporator has been developed in Finland. The invention makes it possible to build large, corrosion resistant heat transfer surface areas at low cost, thus reducing the cost of evaporation. The concept can also be applied Multi Effect (ME) evaporation in cases were low value waste heat and cooling water is available. This paper describes design and operating principles, technical and economical features of the technology. Typical power consumption figure of an evaporating plant is 8.5 kWh/ton (32 kWh/1000 US Gallons) of water evaporated including all pumps. General plant concepts for treatment pulp and paper industry effluents are presented. A test project “closing up bleach plants” is going on in a ECF pulp mill in Sweden. General project information is presented. Description of a plant for process water purification and effluent treatment in a 200 ton/d recycle paper mill located in the Middle East is given.