Falling Film Evaporator and Concentrator Fouling In an RDH Bleached Pulp Mill ...", 1998 International Chemical Recovery Conference Proceedings
In 1996, our mill completed an upgrade of its pulping and chemical recovery systems. Among other things, the upgrade included a new two effect falling film super concentrator capable of producing 80% product solids and a four effect falling film evaporator train powered by the flash vapor from the super concentrator. The original six effect falling film evaporator set was to remain in operation at a lower product solids, and the original concentrator (a twin heater high solids crystallizer) was to be downgraded from 68% product solids to 50%. Initially, the units did not perform as expected. There was severe fouling in both the old set and the new set which limited mill production. Although the fouling has not been eliminated completely, it has been reduced and production rates have been increased to nearly full design capacity. The trials and process modifications that led to these improvements are detailed below.
Falling Film Evaporator and Concentrator Fouling In an RDH Bleached Pulp Mill ...", 1998 Intern