Waste Heat Pre-Evaporation - Technical Paper

Waste HeatPre-EvaporationA.H. LUNDBERG ASSOCIATES, INC. CORPORATE OFFICES P.O. Box 597 Bellevue, WA 98009-0597 (425) 283-5070 FAX (425) 283-5081 www.lundbergassociates.com sales@lundbergassociates.com The growing challenges for pulp mills in the years ahead are highlighted by concerns for reduced energy consumption and improved effluent control. This is often compounded with the difficulty of low grade waste heat utilization. The Lundberg Associates’ Pre-Evaporation system is designed to meet this challenge. The Pre-Evaporator can be incorporated in heat recovery systems for either continuous or batch digesters, concentrator systems, condensate stripping systems, or any other system with unused low grade heat. This heat is converted to additional evaporation capacity to help debot-tleneck an overloaded evaporator, or make avail-able another cost effective alternative for capacity increases. Processing 100% of the mill’s weak black liquor inventory in the pre-evaporation system removes most of the volatile TRS and methanol. This allows the process condensates from the multiple effect evaporators to be reused without the need for treatment. · Effectively removes 99% of the volatile TRS compounds from the black liquor · Typically strips in excess of 85% of the methanol from the black liquor · Concentrates these foul components into a minimal flow · Tubular falling film or LTV technology is available · Virtually 100% turndown · Minimal operator attention · Forgiving during swings in production rates