Spinning Bath Evaporator Availability and Reliability Enhancement Proposal

A single-stage evaporator with natural circulation was used to densify the plasticizing bath through continuous evaporation and to prepare a solution used in the production of viscose fiber. During the process, sodium calcium sulfate salts were formed, leading to fouling of the heat transfer surfaces in the heat exchangers. This fouling created a layer of deposits that gradually reduced the efficiency of the evaporation process in the evaporator. It was determined that a processing medium with a volumetric flow rate of 6 m³·h⁻¹ required a heat exchanger power of 1448 kW. A fouling layer with a thickness of 0.1 mm reduced the heat exchanger's performance by approximately 40%. When the fouling layer increased to 0.5 mm, the heat exchanger power decreased by nearly 74%, down to 889 kW. The purpose of this paper was to analyze the process parameters of the densification technology in order to identify potential optimisations that could increase equipment availability and reliability. Alternatively, the study aimed to provide recommendations for design modifications to the existing technology.